San Clemente is an early 12th century minor basilica, a titular and conventual church built on top of the ruins of a late 4th century church, itself on top of important ancient Roman remains. The postal address is Via Labicana 95, which is the convent; the usual entrance for visitors is the side one, in Via di San Giovanni in Laterano. This is in the rione Monti.

Pictures of the church at Wikimedia Commons are here. There is an English Wikipedia page here.


The dedication is to Pope St Clement I.

The Diocese has a rule on church names, which gives priority to parish churches even over minor basilicas. Hence, officially San Clemente refers to San Clemente a Monte Sacro and the basilica is San Clemente al Laterano. Few people take any notice of this in real life -although the author of the Italian Wikipedia article has.

There is a third church dedicated to the saint in Rome, San Clemente al Castello di Torrenova which is an old Campagna farmstead chapel now deconsecrated.

The three layers of archaeology beneath the present church has led to the rather silly nickname of "Lasagne Church".

The saintEdit

History and legendEdit

The revised Roman martyrology (2004) states that St Clement was the third pope of Rome after St Peter, that he wrote an extant genuine letter to the church at Corinth (known as the First Epistle of St Clement), and that he was martyred about the year 100. The letter is the oldest Christian document that we possess after the New Testament.

The legend of his life and martyrdom is now regarded as fictional, although it obviously influenced the artworks of his church. According to it, he was a high-status Roman who helped St Peter in his ministry at Rome and was exiled by the government to what is now the Crimea (then known as Chersonnesus). There he was martyred by being tied to an anchor and thrown into the sea, which miraculously receded so that his body could be recovered. An ancient anchor was a trapezoidal stone with a hole at the narrower end, but his symbol is now the more familar ship anchor. 

His alleged relics were brought to Rome by SS Cyril and Methodius in the 9th century, and enshrined here. 

The state of the Christian church in Rome at his death in the year 100 is one of the most obscure in its history, but vitally important because it was evolving away from being an unrespectable and heterodox Messianic Jewish sect (one of several) which expected Christ to return in the very near future. The Roman authorities under Nero could distinguish Christianity and mainstream Judaism by the year 64, because the emperor was able to launch a pogrom and treat Christians as vermin (something he could not have done to Jews). Forty years later, the Christian population historically would have been of low or no status, and was probably being administered and sponsored by Greek-speaking people who would have made their money in the mercantile and manufacturing trades. 

The legend involving the Crimea is anachronistic, because it refers to a time after the Imperial government had moved to Constantinople in the year 330. Only then were important troublemakers exiled there, and St Clement would not have been important even as a troublemaker to anybody apart from his co-religionists. Hence the relics now enshrined in the basilica are almost certainly spurious and belong, at best, to another, later Clement.

Which Clement?Edit

The historical witness is further confused by reference to two other Clements who have been claimed as associated with this church or responsible for its dedication. The first is St Clement of Alexandria, who was a very important theologian in Alexandria, Egypt at the end of the 2nd century. His full name was Titus Flavius Clemens, and the place where he died is unknown. Rome has been suggested, on absolutely no evidence.

However, there was an earlier Titus Flavius Clemens in Rome, a consul who was executed in the year 95 by the emperor Domitian on a charge of "atheism". Later Christian writers seized on this as a reference to Christianity (again based on no evidence), and created a confused legend involving him and his wife Flavia Domitilla. The Jews, in their turn, claimed that he became one of them. The legend included the speculation that the original church on this site was in the palazzo of the family of Titus Flavius Clemens.

The really interesting thing about this is that, in 1727, Cardinal Annibale Albani, who was the titular here, published a monograph entitled Titi Flavii Clementis Viri Consularis et Martyris Tumulus Illustratus. In it, he claimed that he had found an epigraph in the church two years earlier extolling Titus Flavius Clemens as a martyr. This has been used, with thin excuse, to claim that the church was originally dedicated to him.

The suggestion that Pope Clement and this Titus Flavius Clemens were one and the same person is still to be found. This is a simple historigraphical fallacy, one that assumes that identical names in different ancient sources sharing the same date and location must automatically refer to the same person. Unfortunately, scholarship on the early church has been afflicted with a lot of this sort of nonsense.


Problem of originsEdit

The present San Clemente was built around 1100. Below it is a late 4th century church, and below that two ancient Roman edifices. In one of these, it has been claimed that Christians worshipped until the 4th century church was built.

Historians before the 20th century thought that this oldest level was the location of the Titulus Clementis, one of the first parish churches in Rome. Further, they identified it with the palazzo of Titus Flavius Clemens, mentioned above. Hence, when excavations began under the church in the early 19th century the excavators were expecting to find this late 2nd century house church. What they did find was a pagan temple, a Mithraeum or Temple of Mithras which belonged to one of many 1st century mystery religions in competition with Christianity in Rome. Next to this were the remains of a very solid structure, which they identified as the expected palazzo.

Suffice to say that modern archaeologists flatly disagree. This edifice was not a private dwelling, but might have been the Moneta (or Imperial mint for coinage). There is evidence of substantial alteration to this in the 3rd century, which modern publications suggest might have been as a result of conversion to Christian use. Unfortunately, no evidence of Christian activity has been found at all here to support this act of wishful thinking.

The archaeological evidence under this church illustrates a wider issue. We have evidence of Christians in Rome in the third century AD from their activities in the catacombs. However, within the city walls what has been found is virtually nothing. This negative evidence is now thought to be significant, especially since several Mithraeums have turned up as an example of evidence of a rival religion's activity. It is now thought that Christians in Rome had no public buildings or churches within the walls before the fourth century. Further, for some reason they refrained from decorating their private places of worship (inside their houses) with recognizably Christian motifs. Hence, their places of worship are now not identifiable in the archaeolgical record.

Titulus and JeromeEdit

A further shift in historical opinion is that it is no longer automatically assumed that the sites of the old tituli (see Titulus) correspond to the modern churches with the same names. This affects the first apparent documentary reference to the church, which is in a work entitled De Viris Illustribus  written by St Jerome in 392. In its short biography of St Clement, he describes how the saint had a well-established church dedicated to him in Rome. This could, however, have been located elsewhere.

First basilicaEdit

Proper churches began to be built in Rome after the Edict of Milan was passed in 313, allowing Christians to practise their religion openly. However, the official Christian cult as prompted by the Imperial authorities was not regarded with favour by the old elite of the city, and this can be discerned from the pattern of church building for the rest of the century. The centres of pagan cultic activity, especially around the Forum, were avoided.

The first possible documentary evidence of the basilica comes from the pontificate of Pope Siricius (384–399), when a church dedicated to St Clement is mentioned. This accords with the epigraphical evidence discovered in the ruined basilica, although some scholars would prefer a slightly later date in the early 5th century. The Mithraeum probably continued to exist until 395, when all pagan cults were outlawed by the emperor Theodosius I, and there is evidence that it was vandalized when it was forcibly closed (clearer evidence exists at the Mithraeum at Santa Prisca). Hence, a date after 395 is very likely for the beginning of construction.

To build the new basilica, the 3rd century building that succeed the possible former Moneta was mostly demolished -although fabric was left to be incorporated into the new church. This occupied about half the area, with the rest taken up by an atrium -although it is not known how far the Moneta extended in that direction. Further, the Mithraeum was filled with rubble to provide a foundation for the apse of the church.

Dark agesEdit

The church immediately obtained a high profile among the city's churches. A papal council were held here in 417 under Pope Zosimus (giving the latest possible date for the church's completion), when a Pelagian heretic called Caelestius was condemned. There was another one in 499, under Pope Symmachus.

Pope John II (533–535) was a great benefactor of the church - he had been cardinal priest of San Clemente from c. 532 until his election as pope in 533. His monogram can be seen inscribed on several slabs of the schola cantorum, and also a fragment of a ciborium was excavated with the inscription presbyter Mercurius (his name before becoming pope).

Pope St Gregory the Great is on record as having preached two extant homilies here at the end of the 6th century. He also left a record of St Servulus  who was a paralyzed begger who used to beg in the atrium at the door of the church and then share his alms with other poor people. Pope Gregoy met him here, and preached a sermon about him. He is enshrined beneath the altar of the Blessed Sacrament (in the chapel of the Rosary), to the left of the high altar.  

Throughout this period and into the Middle Ages, the church was served by Roman diocesan priests. It has been erroneously assumed that a Benedictine monastic community existed at San Clemente from the 6th century, but this assertion is part of the fabricated foundation legend invented in the early Middle Ages by the Benedictines for themselves. The Dialogues attributed to Pope Gregory (the authenticity of which are disputed) includes a biography of St Benedict, and so mediaeval Benedictines imagined that the Pope and all the monks in Rome were Benedictine. They were not, although Pope Gregory employed monk-priests in several churches in preference to secular ones -a policy that was seriously resented, and immediately reversed after his death.

In 637, the alleged relics of Ignatius of Antioch were brought to Rome by Syrian refugees from Islam, and enshrined here. In 867 the alleged relics of St Clement were enshrined with them after being brought to Rome by SS Cyril and Methodius.

The basilica was restored in the 8th and 9th centuries, as can be deduced from the surviving remains.  The 9th century work was probably the result of a series of strong earthquakes, which are thought to have been the major cause of the ruination of the city's ancient monuments. The historically obscure depopulation of the church's neighbourhood probably occurred about this time, and the ruination raised the ground level. The Caelian Hill was destined to be covered by vineyards for the next thousand years or so.

Second basilicaEdit

According to tradition the church was severely damaged in 1084, in the sack of Rome by the Normans of southern Italy under Robert Guiscard, and that was why it was rebuilt. However, it was used as the venue for the conclave to elect Pope Paschal II in 1099 and so must have been fairly intact. He had been the titular priest here, and immediately on election he arranged with the new titular, named Anastasius, to have the church rebuilt.

This was done by demolishing the structure above a level of five metres from the floor, filling it in and building a new church on the platform thus created. The raising of the level by five metres is an indication of how much the ground level had risen since the 5th century, and is one of the few pieces of evidence to date the process of abandonment of those neighbourhoods of the city located on the hills. The shrunken city was already huddling on the river's floodplain, where it was easier to obtain water once the aqueducts had collapsed.

Examination of the old church shows no evidence of destruction by fire, as alleged by the tradition. The most likely reason for the rebuilding was that the location of the floor below ground level meant that the old church was being continually flooded in wet weather.

The new church was consecrated in 1108. The schola cantorum from the old church was dismantled and re-erected in it; we can be grateful that the builders wanted to save some money.

Middle agesEdit

In the Middle Ages, and up to the end of the 16th century, the church was in the countryside and had no pastoral function apart from ministering to pilgrims. Back then, the only nearby road was the present Via Labicana which was also the main route from the city to the Lateran. The Via dei Santi Quattro Coronati was simply a donkey track, and the access to San Clemente and the convent of Santi Quattro Coronati was by a short lane on the line of the present Piazza di San Clemente. There was no road up onto the Caelian Hill, which was given over to vineyards (no mediaeval Roman would drink water if he did not want to die of some horrible disease). There was a lane (now lost) leading north from the other side of the Via Labicana to Santa Maria Maggiore via the Sette Sale, which had a bad reputation because of bandits.

In 1403 Pope Boniface IX handed the church over to the newly founded Augustinian Congregation of St Ambrose, also known as Ambrosians. This was the beginning of the church's conventual status. They continued to serve the church until the congregation was suppressed by Pope Urban VIII in 1643

Pope Sixtus V, as part of his campaign to provide the city with a decent road system, had a new road built from the Colosseum to the Lateran along the side of the church at the end of the 16th century. In response, urban development sprang up along the new road as far as the church -although not any further until the 19th century. This Via di San Giovanni in Laterano took over from the old Via Labicana as the main traffic artery in the area until modern times.

17th and 18th centuriesEdit

After the Ambrosians had been shut down in 1643, Dominicans from San Sisto Vecchio took over in 1645. However, this community was replaced in 1697 by expatriate Irish Dominicans who moved from Santi Giovanni e Paolo. The Catholic Church had been viciously persecuted in Ireland by the British especially under Oliver Cromwell, and many of the clergy had been expelled including the Dominicans here. The church was granted to them in perpetuity on the intervention of Cardinal Francesco Maidalchini (who was not the titular priest here), and they remain in charge.

By the 18th century, the church was in a very poor state of repair. Pope Clement XI (1702–1715) ordered a restoration, with Carlo Stefano Fontana as architect, and it seems that this involved the beginning of the curiosity about what was to be found under the edifice. Work was done on the roof, the façade and the campanile, but the main focus of attention was on the convent the accommodation of which was grossly inadequate.

Carlo Stefano Fontana was the nephew of the famous architect Carlo Fontana, and the two have been confused. The latter was already dead when this work was done.

The present appearance of the church is as a result of this restoration, as there has been no re-ordering since except for the high altar.

Modern timesEdit

The first systematic excavation of the lower church was carried out by Fr Joseph Mullooly O.P. He had been made superior of the convent in 1850, and in 1857 began work to clear the rubble out of the voids under the upper church. This was not done with the care that modern archaeologists would expect, but then the discipline was in its infancy at the time. However, Giovanni Battista de Rossi provided valuable professional help. Workmen were employed to fill baskets with rubble, carry it up and out and (apparently) use it to fill potholes in the streets. If any carved or painted fragments were spotted, well and good.

In 1861, it was realized that a full-sized lower church existed. In 1863, the shrine of SS Cyril and Methodius was uncovered, and then the work proceeded in the lowest, ancient Roman levels up to 1870. Fr Louis Nolan O.P. carried out further excavations 1912–1914, and in 1936 a small set of catacombs was discovered. Since then, work has been going on more or less continuously and results of excavations are still being published. A "recent" discovery has been the church's 6th century baptistery (very poorly written up as at 2016).

The high altar with its confessio or shrine-crypt was altered in 1868.

At present, the church is very popular with tourists. Most of them come here specially, since the church is not on the way to anywhere else on the mainstream tourist circuit. 


Despite being an ancient titular church, a systematic list of cardinals only exists from 1331.

The current titular priest of the church is H.E. Adrianus Johannes Simonis, Archbishop of Utrecht.


Layout and fabricEdit

The church is on a classical basilical plan, with a central nave having arcaded side aisles and an external semi-circular apse. The central nave has a pitched and tiled roof, except for the entrance loggia and a range of rooms over it. This portion is 18th century and has its own, slightly lower roof. 

Unusually for a church this size, there is only a single entrance in the façade and the near ends of the side aisles are occupied by chapels. The left hand chapel, that of St Catherine of Alexandria, has a campanile perched over it.

At the far ends of the side aisles are two more chapels which are external to the main structure. The left hand one, of the Rosary , has a three-sided apse and the right hand one, of St John the Baptist, has a small segmental one. Off the right hand aisle is a large square external chapel with a dome and a semi-circular apse, and this is dedicated to SS Cyril and Methodius.

In front of the church is a large atrium or courtyard with an entrance block, and beyond the right hand side of the church is the convent. 


This has a simple L-shaped layout around a garden in the corner of the Via Labicana and the Piazza di San Clemente. There is no cloister, and no features of interest in the fabric itself except for a striking chimney that you can see from the Via Labicana. This has a pyramidal cowl and a corbelled cornice, and looks rather like a minaret.

However, if your visit involves getting off a bus or tram at the Via Labicana, take a moment to have a look at the convent gateway. This is on the other side of the convent's street frontage, to the west of the garden. It is naïve Baroque, with a large archway of massive rusticated blocks with a recessed tablet showing the convent's heraldic shield above. Two pairs of gigantic double curlicues flank the composition.


The mediaeval church had a standard Romanesque brick campanile at the bottom of the right hand aisle, with two storeys above the entrance and a tiled pyramidal cap. This was demolished in the 18th century restoration, and replaced by one over the near end of the left hand aisle. This has two storeys above the central nave roofline, the lower one almost cubical and the upper one forming a tall aedicule with a single large arched soundhole on each face. The lead cupola is complex in form, and has a cushion base of two steps on which an overhanging ogee curved form is placed. There is a ball finial.

Side frontageEdit

Carlo Stefano Fontana took a little trouble with the left hand side frontage on the Via di San Giovanni in Laterano, because this was the main public interface of the church. Here, the street is at an angle to the wall of the church and atrium and so there is an attractive, narrow piazza which now has mature trees.

The church's side wall has five large rectangular windows, and an ornate side entrance which is the usual one for visitors. If you are waiting for the church to open, it is worthwhile having a look at the latter.

This has a molded doorcase, flanked by a pair of little Ionic pilasters with humourous capitals. The volutes are carved to look like horns springing from a putto's head, and are embellished with a garland. Note the brackets for oil lamps on either side of these capitals. Above, there is a triangular pediment broken at the top and set directly onto the lintel (no cornice); inside this is a pair of cardinal's heraldic shields acting as posts for a smaller, raised segmental pediment broken at the cornice. There is an empty plinth between the shields, and something (a statue?) has obviously gone missing.

Instead of over the lintel, as was traditional, Fontana placed the dedicatory inscription over the pediments and gave it a floating gable. The inscription is on an ornate Baroque tablet, and reads: Clemens XI Pont[ifex] Max[imus] restauravit et ornavit, anno MDCCXIX, pont[ificii] sui IX. The sides of the setting of the tablet sweep down to a pair of tondi either side of the lintel, which look as if they had something to do with the oil lamps just mentioned.

Ceremonial frontageEdit

The main entrance of the church is not here, but on the Piazza di San Clemente round the corner. This is not a real piazza, but a short wide street from the Via Labicana. When the latter street was raised here and levelled out at the start of the 20th century to turn it into a main road and a tramway (which is still there -number 3), the Piazza was ramped to maintain a steady gradient. This put the church's entrance in a hole, unfortunately.

The frontage is not pretty, being a rather grim blank wall with four little square windows near the roofline. It belongs to the original mediaeval priest's house, and in the wall you can see signs of blocked windows. Somebody was worried about security at some stage.

The single entrance is protected by a prothyrium or porch, which stands on four ancient columns with different ancient capitals; the front two are Ionic, and the back two Corinthian. The large entrance arch has a gable with corbels over it, and this is duplicated on both sides. Above, there is a tiny chamber (the old English word is parvis), with a single window on the left hand side. This would have been for the doorkeeper in the old days. A similar arrangement exists at San Cosimato in Trastevere.


The entrance through this prothyrium is not always open. If it is, you can enter the atrium and see the façade of the church. If not, you have to go through the church's side entrance and hopefully out again through the main door; this is usually open, except sometimes when the weather is bad.

An atrium may look like a monastic cloister, but has a different function. Many old Roman churches had one, although most have been lost. It is a courtyard outside the main entrance of the church, usually with covered walkways on three sides and sometimes a loggia on the fourth side which is the church façade. The function was as a public ancillary area, for such things as organizing processions, selling food or devotional objects, having meetings and socializing. None of these, especially the last, was done in the church itself.

The atrium here consists of a courtyard paved with random fragments of stonework, obviously some of the rubble dug out of the lower church. There is a rather miserable little squirt of a fountain in the middle, and two palm trees in positions where you would expect the obelisks of an Egyptian temple to be if the church were one. Down the sides are colonnaded walkways which are not arcaded, but trabeated (post-and-rail design). The entrance walkway has an arcade under the mediaeval house, with three arches on massive unadorned pillars.

If you look at the right hand corner of the atrium when facing the church, you will see that the atrium is actually slightly wider than the church itself. 

The atrium has six ancient columns on each side, with assorted ancient columns and bases. A few are Doric, but most are Ionic. These columns, together with those in the loggia, were all originally looted from a very high-status ancient Roman building, and were almost certainly first used in the lower church. Most are grey granite. This is not impressive to modern eyes, but to ancient Romans the stone counted as semi-precious. This was because of the hardness (one column could take man-weeks to cut and polish) and exotic source of the stone. The quarry was at Mons Claudianusin the Eastern Desert of Egypt and a truly inaccessible, horrible place.

A pair of the side columns in the atrium are of pink granite, and this was sourced from Aswan in Egypt, even further away although accessible by boat up the Nile.

One of the walks has a wall tablet with an inscription composed by Pope Clement XI in praise of the church. In the corner to the right of the church entrance is a monument in the form of a chest with a convex lid, which celebrates the invention of the Glagolithic alphabet by St Cyril. The epigraph on it is in this script (despite popular belief, St Cyril did not invent the modern Cyrillic alphabet which came later).

The atrium is a pleasant place to chill out in fine weather.


The  mediaeval façade had an external narthex or loggia, with the arcade of the same design as the one there now. There was a single-pitched tiled roof, and the frontage of the nave above this had a small central oculus (round window) flanked by a pair of small round- headed windows.

The narthex was demolished and rebuilt in the early 18th century by Carlo Stefano Fontana, who saved the ancient columns and replaced them exactly as found. In doing so, he converted the external narthex into an internal loggia by adding an ancillary room over it, and so created the present façade. This is in a very sober Baroque style, in two storeys with an unusual paucity of decoration.

The first storey comprises the loggia, with an arcade having four ancient Ionic columns of the same sort as in the atrium. Rather odd arrow-shaped devices are inserted into the spandrels between the archivolts. Over the arcade is an entablature with posts (short pilasters) in shallow relief above the column capitals, and a molded and tiled cornice and a blank frieze.

The second storey starts with an attic, also with posts. This stretches for the width of the first storey, which covers the ends of the aisles as well as the central nave. The rest of the storey fronts the latter only, and has four Corinthian pilasters on plinths, supporting an entablature with posts and a blank frieze. Above this is a pediment with a blank tympanum. There is a very large round-headed central window. The sides of this storey are embellished with a pair of sweeps ending in gigantic volutes, and over the ends of the attic is a pair of ball finials matching that on the campanile.


Layout and fabricEdit

San Clemente floor plan

The layout is classically basilical. There is a central nave with side aisles, no transept and a large apse with a conch containing the famous mosaic. The side aisles have chapels at each end. The left hand aisle has the chapel of St Catherine of SIena at the bottom and that of Our Lady of the Rosary at the top, while the right hand aisle has those of St Dominic and St John the Baptist in the same locations. The external chapel of SS Cyril and Methodius is through a doorway off the right hand aisle.

The excavations below the church are accessed through a door at the bottom of the right hand aisle, where you'll find a shop and the ticket booths. This area is outside the church itself.


The nave has two arcades on each side, separated by a wide pillar. Each arcade has four ancient Ionic columns, making a total of sixteen in all; the far pair are in the sanctuary, and the near pair are incorporated into the two side chapels flanking the entrance. These columns are a mixed lot from different ancient buildings. Some are ribbed, and overall are of slightly different lengths. You can see how the church builders had to insert packing slabs under the bases of some of them to maintain the right height. The veined marble ones are cipollino, from Euboea in Greece.

The nave walls above the arcades have windows, altered in the 18th century restoration. In between the windows there are fresco panels by different contemporary artists, as follows: St Flavia by Sebastiano ConcaSt Clement Bringing Water From a Rock by Giovanni Antonio Grecolin, St Clement with the Anchor by Giovanni OdazziTranslation of the Relics of St Clement and The Death of St Servulus by Tommaso Chiari, St Ignatius of Antioch by Gian Domenico Piastrini and St Ignatius with the Animals in the Amphitheatre by Pierleone Ghezzi.

The frames of these pictures, as well as the windows and the intradoses of the arches of the arcades, are embellished with stucco decorations. These are in an overall white colour scheme, a very neat way of empasizing the gilded splenour of the ceiling and the apse mosaic.

The impressive ceiling is of the same restoration, with complex coffering in blue and gold and featuring the heraldry of Pope Clement XI. The single star on his coat-of-arms occurs in the décor. The central fresco panel features The Apotheosis of St Clement, and is by Giuseppe Chiari. He also supervised the other artists in the nave painting project.

The counterfaçade, over the entrance, features SS Cyril and Methodius by Pietro Rassini. The same artist executed frescoes of Our Lady on the ceiling of the left hand side aisle, and St Servulus on that of the right hand one.


The floor of the church is one of its glories. It consists of a variety of ancient polychrome stones, mostly marbles, cut in geometric shapes and tessellated. This style can be found on many church floors in Rome (although much has been lost), and is usually known as Cosmatesque after a famous artisan family of the 12th century. The term needs qualification; real Cosmati output involved delicate inlays on church furnishings (you can see some on the schola cantorum), and the family were inspired by already existing floors.

The technique of fitting different shapes of coloured stone together to make a patterned floor is better known as opus sectile, and was popular in ancient times (you can see examples at Hadrian's villa at Tivoli, and also at Ostia). It is thought that the style was re-imported into Sicily from the Byzantine Empire in the 10th century, and hence spread to Rome and the rest of Italy in the early Middle Ages.

The style is also known as opus alexandrinum, and the distinction between this term and opus sectile is confused and depends on the author.

The display here of different stones amounts to a geological sample kit. The bright yellow stone is giallo antico, which the ancients called marmor numidicum. It came from a quarry in what is now Chemtou in Tunisia, and supplies were already running out in the 3rd century. Most yellow marble in Rome is from Siena, and giallo antico can usually be distinguished from this by its apricot tint with a hint of orange. This marble can have deep red veins, and you can find some little bits of this in the floor if you look.

The dark green stone is the ancient lapis Lacedaemonicus, which is a serpentine from Sparta in Greece. It is often mistakenly called a basalt, or "green porphyry" (sic), and is common in Roman churches.

The pink bits look like marmor Chium, from the Greek island of Chios, or rosso antico from Cape Matapan on the Peloponnesus. You can tell the difference because the former is a breccia, looking as if it is made up of fragments combined.

The dark red stone is the famous imperial porphyry, from Mons Porphyrites in the Eastern Desert of Egpyt. Porphyry as a stone occurs worldwide, but this variety came from the one place and has been unobtainable since the 4th century. It is distinguished by its deep crimson colour with whitish speckles, which are phenocrysts. The colour mimics the Tyrian purple dye obtained from sea-snails in the eastern Mediterranean, which was a very high-status product in the ancient world because its production was very labour intensive. Also, unlike almost all ancient dyes for clothes it was colour-fast in washing.

(The word "purple" in English now correctly means a colour created by mixing red and violet, which is not the original purple colour as you can see from this stone. However, modern English often interchanges the words "purple" and "violet" -which are different colours.)

The floor has been carefully restored, and also had a tomb-slab inserted into its middle in 1592. This commemorates VIncenzo Lauro, who was cardinal here.

The name of the original craftsman has been recorded as Magister Paulus.

​Schola cantorumEdit

The schola cantorum and associated sanctuary screen dates to the 6th century, and originally belonged to the old church below. It was salvaged and re-assembled in the new church at the start of the 12th century, and embellished with Cosmatesque inlay work. 

The structure is made up of marble slabs set on end, called transennae, with some of them bearing the monogram of Pope John II who ordered the original work. In the old church it had two sets of benches facing each other, flanked by a pair of elevated lecterns facing the high altar. In the re-assembling the left hand one of these was converted into an ambo or pulpit, and next to this was placed a superb spirally twisted Paschal candlestick.

The enclosure was used for singers accompanying the liturgy. In the 16th century changing liturgical norms required that no structures be allowed to intervene between the high altar and the congregation, and hence most of the scholae cantorum in Roman churches were destroyed. This one survived because by the 18th century its antiquarian value was appreciated; if the Baroque restoration had happened in the 17th century, the schola would almost certainly have been thrown out.

In Baroque churches, the schola is often replaced by cantoria which are opera-boxes raised above floor level for singers and musicians.


The apse is richly decorated with frescoes and mosaics. The curved wall of the apse itself has a 14th century fresco cycle. In the conch and on the triumphal arch are 12th century mosaics which are described here under separate headings.

Starting from the floor, there is a frescoed zone with purely decorative motifs in panels, followed by a border with floral decoration. Then comes a large and impressive fresco panel of Christ and Our Lady with Eleven Apostles. Date palm trees separate the figures, and at their feet is a river with fish in it.

(One may note the incongruity of this, as there should be twelve apostles. The conundrum might be resolved if one agrees that the subject is indeed that of Christ with his usual twelve apostles -but only if the feminine figure to the left of Christ is identified as St Mary Magdalen and not the Virgin Mary, and if one accepts St Mary Magdalen as one of Christ's original apostles. See the Gospel of Mary as found in the Berlin Gnostic Codex or Papyrus Berolinensis 8502. This theory of the saint's apostleship has been promulgated by Karen Leigh King in her analysis of this text, which mainstream biblical scholarship has considered pseudepigraphical. The iconography of the fresco here is suggestive, but too late in date to be of support to the theory. Actually the eleven apostles and Our Lady are depicted as listed in Acts 1:13-14, where they are the nascent church in Jerusalem after the Ascension).

The triumphal arch is supported by a pair of pilasters in shallow relief with un-classical capitals deriving from the Corinthian (with swags instead of acanthus leaves). These are obviously 18th century.

The high altar has a 12th century ciborium or baldacchino, similar in style to that of San Giorgio in Velabro. It has four Corinthian columns in pavonazzetto marble supporting a rectangular cornice, on which are six little columns at front and back and five on each side. These in turn support a pitched roof with pediments at front and back; on the tympanum of the front pediment is St Clement's anchor.

Beneath the high altar is the confessio or crypt installed in 1868. The tombs are here of St Clement (enshrined in 868) and St Ignatius of Antioch (believed to have been thrown to the beasts in the Colosseum, although no record survives of his death). The inscription on the front of the altar mentions Saint Clement: SANCTUS CLEMENS MARTYR HIC FELICITER EST TUMULATUS; "Saint Clement, martyr, is happily buried here". Below the altar is the inscription: "HIC REQUIESCUNT CORPORA SS CLEMENTIS PAPÆ ET IGNATII" (Here lie the bodies of Saints Clement and Ignatius).

Behind the altar is an ancient bishop's throne, saved from the old basilica. The back was once part of the shrine of a martyr - the word MARTYR is inscribed on it.

Caetani tabernacleEdit

To the right hand side of the apse is an early 14th century tabernacle, executed in French Gothic style with Cosmatesque decoration. It is placed rather high on the wall, so that it can be seen by all; in addition, it is "out of reach of profane hands", as the Lateran Council in 1215 had decreed.

This tabernacle was commissioned by Cardinal Giacomo Tomasi Caetani, titular priest of the church, in 1299. The artist was Arnolfo di Cambio. Above the tabernacle door, Cardinal Caetani is depicted in a relief kneeling before the Blessed Virgin and the Child Jesus, with his patron St James the Apostle (Giacomo is the Italian form of James) directing him toward the divine presence. At the top of the canopy is a medallion with the Lamb of God in relief.

This tabernacle is not now used for the Blessed Sacrament, which is required to be enshrined at an altar.

Triumphal arch mosaicEdit

The mosaics are among the finest in Rome. They are from the 12th century, but look earlier since they are in the Byzantine style, obviously still influential in Rome at the time. The appearance is dominated by the golden glow of the background, which was achieved by applying gold leaf to the backs of the clear glass tessarae used for it.

Postcards with details of the mosaics are sold in the shop. It is a good idea to buy this set of postcards, and then to take them back into the church for reference when looking at the mosaics - this should help you to understand them better when identifying motifs. (Profits from the shop are put towards keeping the church in repair.)

If the church had a transept, the mosaics on the triumphal arch and apse conch would be separate as is the case at San Paolo fuori le Mura. Here, they are combined. 

At the top of the composition on the triumphal arch is the figure of Christ Pantokrator (All-ruler), flanked by symbols of the four Evangelists (lion, ox, man, eagle). Christ is in a circular tondo, recalling the great image of him in the oculus of the dome of the great church of Hagia Sophia in Constantinople. Directly below Christ, on the intrados of the arch, is the Chi-Rho symbol with Alpha and Omega. The rest of the intrados is mosaicked with flowers and fruit, depicted as coming from a pair of vases at the lower ends.

On the spandrels , a bit lower than Christ, are four persons. On the left, St Lawrence receiving instruction from St Paul. St Lawrence is sitting with his feet on an iron grille, the instrument of his martyrdom. St Paul is identified with an inscription, AGIOS PAULUS. This curious blend of Greek (Agios = saint) and Latin (Paulus rather than Greek Paulos) possibly refers to his Eastern origins. The inscription below them says DE CRUCE LAURENTI PAULO FAMULARE DOCENTI, "The servant Lawrence is taught about the cross by Paul". The Latin is bad, and a main verb is missing; famulare is read here as famularis est.

On the right are SS Peter and Clement. This figure refers to the succession of Bishops of Rome; Peter declares Christ's presence to his later successor. The inscription says: RESPICE P(ro)MISSUM CLEMENS A ME TIBI CH(rist)UM, "Behold, Clement, Christ as he was promised to you by me". Clement holds the anchor which is his symbol (this is partly obscured by a Baroque cornice), and below the pair is an oared galley with two fish.

Below these four figures are two prophets. On the left, Isaiah holds a scroll saying VIDI DOMINUM SEDENTEM SUP(er) SOLIUM, "I saw the Lord seated on a throne". On the right, Jeremiah is also holding a scroll, saying: HIC EST D(eu)S N(oste)R ET N(on) ESTIMABIT(ur) ALIUS ABSQ(ue) ILLO, "This is our God, there is none to compare with him".

Below the prophets, at the bottoms of the composition, are two cities; Bethlehem on the left with the angel Gabriel, and Jerusalem on the right with St Peter's cock (male chicken that crowed).

Along the edge of the archivolt is another inscription, saying: GLORIA IN EXCELSIS DEO SEDENTI SUP(er) THRONUM ET IN TERRA PAX HOMINIBUS BONAE VOLUNTATIS, "Glory to God in the highest, seated on the throne, and on earth peace to men of good will". Taken together with the scroll held by Isaiah, two elements of the Mass are referred to. The verse held by Isaiah is connected to the preface given before the Sanctus, and the other text of course refers to the Gloria.

Apse mosaicEdit

The vine with curlicued foliage that dominates the apse mosaic is a symbol of the living Church, with its roots in the Garden of Paradise and its fruit, the Cross of Christ (more information on this below). 

The composition is described from the bottom to the top:

At the bottom, Christ and the Apostles are depicted in mosaic in the form of the Lamb of God flanked by a flock of twelve lambs. Actually, they are all depicted as full-grown sheep (as was the iconographic tradition), standing on a flowery meadow. Spot the snail.

An inscriptions follows, explaining the meaning of the main mosaic at the top:
The line divisions here are marked by crosses placed between verses in the inscription. It is not easy to penetrate the inscription at first glance; one must take the first and last lines together as one part of it, and then the second and third line. The first and last line read: "We represent the Church of Christ as this vine, which the Law dries up but the Cross makes to be green." The second and third lines say: "[Part] of the wood of the Cross and a tooth of James, as well as of Ignatius, rest in the above-delineated body of Christ". It might seem like a mystic code, but it simply refers to a splinter of the True Cross and relics of St James the Apostle and St Ignatius of Antioch, which were placed behind the body of Christ in the mosaic itself when it was made.

Directly above the inscription, in the centre, are two deer and six birds at a fountain which is branching into four streams; this is an allusion to the description of the Garden of Eden in Genesis 2, 9-10. The deer are a reference to the first verse of Psalm 43: "Like the deer that yearns for running streams". The birds are very well depicted; two egrets, a wild duck and a gallinule are represented, as well as a pair of peacocks. Nobody would have seen a peacock in Rome in the 12th century (they come from India), so the drawer of the original cartoon either saw one elsewhere or was familiar with a very accurate Classical depiction.

In the lower corners are several charming scenes of farming life, which repay close examination. These include chickens being fed; as chickens must be fed by humans to survive, we must be tended by the Church to reach Heaven. Sheep are shepherded, referring to the Church tending its flock.

Above the fountain is an acanthus plant, a Classical motif, on which stands a crucifix. The Blessed Virgin and St John the Evangelist are depicted at the foot of the cross, on which are twelve pigeons. These are almost certainly the Apostles, since pigeons can carry messages (here, the Gospel) long distances. 

Within the acanthus plant are a stag and a serpent; these refer to the Fall of Man in the Garden of Eden. The serpent is obviously the serpent that tempted Eve and the stag was, in ancient stories, referred to as the serpent's natural enemy, drawing out snakes from the ground and stamping them to death. 

Two pairs of tendrils shoot up from the acanthus. One pair curves behind the Cross and is withered, and may be a symbol of Judaism after Christ (the Synagogue), or of the state of humanity before Christ. The other pair forms twenty-five spiral tendrils on each side, a total of fifty which is the number of days in the Easter season. Each tendril ends in a stylized flower, except for two with bowls of fruit and two with lidded bowls, and in between them are little figures of saints, angels and birds. Note the bird in a cage on the right hand side.

The vine and cross form a reference to the ancient legend that the wood in the True Cross came from the Tree of Life in the Garden of Eden. This legend was probably meant as a cathecetical tool, as it underlines the idea of Christ as the new and faultless Adam. redeeming the old Adam and hence all humanity by his death and resurrection.

Above the cross is the hand of God the Father in heaven with clouds, holding a thunderbolt. This is another Classical idiom, formerly a symbol of Jupiter. The rest of the mosaic up to the apex of the conch is taken up with stylistic designs, except for two representations of the Lamb of God on a plinth.

In summary, the mosaic depicts the Tree of Life, which withered after sin entered the world but then turns into the new Tree of Life, the Cross of Christ which is the ultimate symbol of Christ's victory over sin. To give the mosaic a more powerful impact, a splinter of the True Cross was (as mentioned) incorporated into it.

Chapel of St Catherine of AlexandriaEdit

The chapel of St Catherine of Alexandria is at the bottom of the left hand aisle, immediately to your right as you enter through the church's side door. It in the Gothic style, rather unusual in Rome, and is entirely covered in beautiful early Renaissance (Quattrocento) frescoes which are among the most important of the period in Rome. These paintings are attributed to Masolino da Panicale, and were executed 1428–1431.  Older guidebooks will tell you that they are by Masaccio, but this theory is now discounted. There is still debate as to whether the two artists collaborated in the work to any extent, as they had done at the Brancacci Chapel in Florence.

The chapel is on a square plan, with a simple Gothic cross-vault springing from the corners. Unfortunately it has to be kept gated to stop idiots scratching graffiti into the frescoes, which means that it is difficult to view them.

Above the entrance to the chapel is an Annunciation, shown taking place in an open loggia. The artist is demonstrating his grasp of the newly rediscovered laws of perspective, and not getting them quite right. God the Father appears in a tondo at top centre. Unusually, the model used for the figure of Our Lady was a very attractive bionda who also seems to have posed for the figures of St Catherine within. 

On the left hand entrance pier is St Christopher, having the Christ-Child on his shoulder who in turn is holding the world.  

In the archivolt of the Gothic entrance arch are the twelve apostles, and in the vault itself are Evangelists and Doctors of the Church.

On the altar wall is a Crucifixion, which is the centrepiece of the artistic composition. The fresco is not in very good condition, and has been mutilated in two places. The left hand blank patch marks the location of a tabernacle, while at the bottom right is a long and rather tedious epigraph in honour of Cardinal Benedetto Naro. Amazingly, this latter piece of vandalism was executed in 1832.

The left wall shows scenes from the life of St Catherine, and repays close examination. At the top left the saint is discussing Christianity with the emperor Maxentius in a pagan temple, wearing a blue dress while gesturing towards an idol on a column. The next scene shows her converting the emperor's wife while in prison (a wholly fictitious occurrence), and the subsequent beheading of the latter. Below on the left, the saint converts a group of Roman philosphers while the emperor presides;  they are then burnt by the emperor. (The saint is wearing a black dress here, as it is the following day and she has changed her clothes.) In the middle the saint is being tortured on a pair of wheels (the famous Catherine wheels), which are destroyed by an angel while the emperor looks on. Finally, the beheading of the saint is shown. The large mountain on the right in this scene is Mount Sinai , since the legend has it that her body was miraculously transported to that location and is now to be found enshrined in the monastery dedicated to her there.

The right hand wall has scenes from the life of St Ambrose of Milan. These used to be thought to refer to St Clement, until their latest restoration. A re-setting of the central window as well as rising damp has seriously damaged this cycle.

At the top left, St Ambrose as a baby is visited by a swarm of bees while his nurse trys to wave them away. This legend was an allusion to the honeyed sweetness of his future discourse. At the top right is his election as bishop, when a child in the audience shouted "Ambrose for bishop!". At bottom left the saint and his companions on a journey are fleeing an evil rich man's house as it is swallowed up by the ground. At bottom centre is the saint's study-room (this scene is seriously damaged), and to the bottom right is a death-bed scene.

The chapel was commissioned by Cardinal Branda da Castiglione, an important contemporary patron of the arts. It has been restored several times after neglect which damaged the frescoes, and in the process two sinopie by Masolino were discovered. One is of the Crucifixion and the other of the beheading of St Catherine, and these are now displayed outside the chapel.

Chapel of Our Lady of the RosaryEdit

The chapel at the far end of the left hand aisle is dedicated to Our Lady of the Rosary, because the Dominicans invented the devotion. It is also the Blessed Sacrament chapel, and has St Servulus enshrined under the altar. The altarpiece is by Sebastiano Conca, and depicts Our Lady of the Rosary with SS Dominic and Catherine of Siena.

Here also is a picture depicting Our Lady with the Holy Child and the Infant John the Baptist, by Jacopo Zucchi. The style is not to everyone's taste (fat little boys in the nude are seriously out of fashion in religious iconography), but the execution is good -especially of the flowers.

Located by this chapel are several momuments. Here is an important one to Cardinal Giacopo Antonio Venier, who died in 1479. It incorporates two columns from a 6th century tabernacle commissioned by the future Pope John II (in other words, together with the schola cantorum), and it seems that an important early piece of church furniture was destroyed here in the 15th century. Also, we have a monument to Visconte Bartolomeo di Basterot and his wife by Gaetano Forlivese of 1874, and one to Pietro Salvati from Foligno of 1628.

Chapel of St John the BaptistEdit

The corresponding chapel at the end of the right hand aisle is dedicated to St John the Baptist.  It has a 16th century statue as an altarpiece, attributed to Simone Ghini . The altar is modern, since the chapel has been recently restored. There are remnants of damged frescoes.

Near the chapel are two 15th century funerary monuments. That of Giovanni Francesco Brusati is by Luigi Capponi of Milan, in 1485 and that of Cardinal Bartolomeo Roverella of 1476 is by Andrea Bregno. Giovanni Dalmata executed sculptural details on the latter, notably Our Lady with angels and the Eternal Father.

Chapel of SS Cyril and MethodiusEdit

The external chapel of SS Cyril and Methodius, the apostles of the Slavs and patrons of Europe, is off the right hand aisle. St Cyril's mortal remains were probably interred in the church below after his death in 869 (Methodius died elsewhere), and were not transferred when the church was rebuilt because he was not regarded as a saint back then. This title was only given to him in Rome, with Methodius, in 1880.

This chapel amounts to the Roman shrine to the two saints, and is popular with pilgrims especially from eastern Europe. St Cyril is regarded as the inventor of the Cyrillic alphabet, although he was not responsible for modern Cyrillic but for the Glagolitic script.

The decoration dates from 1888, when the chapel was dedicated to the two saints on the instructions of Bishop Josip Strossmayer. The large altarpiece fresco of St Clement Presenting SS Cyril and Methodius to Christ, as well as the wall frescoes depicting scenes from their lives, are by a painter called Novelli.

Outside the entrance here is a monument to Teodoro Ramsden and his wife, by Forlivesi again in 1874. They were English expatriates living in the city.

Chapel of St DominicEdit

This little chapel is at the bottom of the right hand aisle, and is on the site of the original mediaeval campanile. It contains three paintings depicting scenes from the life of St Dominic, attributed to Conca.


The shop is now located in the former sacristy wing, through a door in the right hand aisle near the above chapel. The stock, especially the postcards, is good. The church depends on the income from the shop, so do patronize it.

4th century churchEdit

Layout and fabric nowEdit

The entrance to the excavations is through the shop, where you also pay the fee. They are extensive, interesting and well described in the many signs down there, so it's worth the money. Especially, signs by the frescoes provide explanations for them -although buying a guidebook is still a good idea.

The access staircase, to the right of where you pay, was installed in 1866. It displays many fragments of sculpture, as well as the 4th century dedicatory epigraph. It emerges at the right hand end of the narthex or entrance porch of the old church. From there, you can enter three zones separated by walls formed by blocking up the original arcades. These divide the area into the central nave (which is unequally divided by a third foundational wall), the right hand aisle and the left hand aisle. At the end of the latter is the staircase down to the next level, the ancient Roman remains.

Needless to say, the vaults and the brick piers are modern. 

Original layoutEdit

What you see gives little impression of having been a basilical church. That's what it was, and it was slightly wider than the newer church above.

The main nave had an arcade on each side, of nine arches each. Above each arch was a window, and these nave windows as a whole were not matched but were of different shapes and sizes. The narthex had one entrance into each side aisle, and a wide ceremonial entrance into the central nave of five archways. It is fairly certain that there was a colonnaded atrium in front of the narthex, like that of the present church, although this has not been excavated.

At the end of the right hand aisle was a sacristy, and there were probably another one on the other side of the apse. The latter was semi-circular, not on the plan of the present apse above but to the right (you can view the old apse behind the foundation wall of the new one). There was no transept.

Originally, the walls of the church do not seem to have been frescoed. The surviving paintings were added later.


Immediately you arrive at the bottom of the last stairs, look to the left and then a bit further to the right, to see poorly preserved frescoes comprising portraits of saints. These are tentatively dated to the 7th century.

In the narthex, which is the first room that you enter, you can see columns embedded in the wall. They originally formed part of an open colonnade, but apparently after an earthquake in the 9th century the supporting wall were added. Frescoes were executed here, probably in the late 11th century just before the church was rebuilt. However, the dates of all the frescoes down here have been disputed; you can find these ones described as 9th century. 

To the left is a fresco of the Last Judgment, showing Christ accompanied by (?) SS Michael and Andrew to the right, and SS Gabriel and Clement to the left. The kneeling figures might be SS Cyril and Methodius, but this is a guess.

Then on the right come two frescoes with scenes concerning St Clement. The first one you come to  depicts a legend set in Crimea, the traditional site of his martyrdom. According to the story, the saint was thrown into the sea with an anchor tied to his neck. Every year on the anniversary, there was an exceptionally low tide as pilgrims visited the site and a little chapel emerged from the waters. One year a child was left behind by accident, and was thought to have perished as the water rose. The next year he was found in the chapel, in good health. The fresco shows the mother finding the little boy in the chapel, with the fish-filled sea around it. The family that gave the painting is also included, and among them is a boy named after the saint - you can see the inscription Puerulus Clemens, "The little boy Clement" written next to him.

The other fresco is on the other side of the entrance into the central nave, and shows the procession taking St Clement's body from the Vatican to San Clemente.

Opposite the paintings is a hinged marble slab. It was originally a pagan memorial, which was later reused by Christians. The pagan epitaph is for a child: "Marcus Aurelius Sabinus, also known as 'the little rover', a most beloved child. He had no equal among the young men of his own rank and time."

​Right hand aisleEdit

The right hand aisle contains fragments of several frescoes. It also illustrates a problem of conservation, as the residual damp in the walls causes them to sweat salt and this will ultimately cause serious damage. Fr Mullooly had the foresight to make painted copies of the frescoes as  he found them, so the already tragic fading that has already taken place can be appreciated.

The first one is a martyrdom of St Catherine, 10th century?

The most important fresco in the aisle is next, in a round-headed niche, and is of the Madonna and Child. It is thought that it was originally of the empress Theodora (died 548), and was converted into a portrait of Our Lady through the addition of the Holy Child and a throne perhaps in the 9th century. This theory depends on the rather striking portraiture of Our Lady, which is thought to resemble the mosaic depiction of the Empress at the church of San Vitale in Ravenna. The figure is (or was) accompanied by two court attendants, according to the theory, who were converted to SS Catherine and Euphemia.

Clemente Theodora

Madonna and Child fresco, potentially Empress Theodora.

There used to be another fresco of Our Lady covering this one, perhaps early 9th century, which fell off soon after discovery.

The other frescoes beyond here are much less well preserved, and are identified hypothetically as the Council of Pope Zosimus, AD 417, and the story of Tobias (basically now lost). 

Towards the end of the aisle is a pagan (1st to 3rd century) sarcophagus carved with the story of Phaedra and Hippolytus. Beyond this is a 7th to 10th century figure of Christ which has been almost completely destroyed -the sarcophagus was found here, and might have been re-used as a tomb or shrine despite the pagan symbolism.

You can see marble columns from the original arcade embedded in the blocking wall. It is a small puzzle as to why these were not salvaged in the rebuilding, as they are of high quality.

Central naveEdit

The central nave is divided into a larger space and a narrow corridor by the inserted foundational wall on the right. It has been made into a sacred space by the provision of an altar at the far end, with a ciborium having a design based on that of the high altar in the church above. There is a curved wall behind the screen wall behind this altar, which is not the original apse wall but a supporting wall for the apse above. The original apse of this lower church was larger, and part of it survives. You can examine the void between the two, shaped like the chopped-off end of a crescent.

After entering the nave, you'll immediately find a 9th century fresco on the left. It depicts the Ascension of Our Lord. It is in the traditional Byzantine iconic idiom for this feast, which means that Our Lady is in the centre surrounded by the apostles. Included in the crowd is St Vitus, and Pope Leo IV (847–855). The latter is depicted with a square halo, which means that the fresco was executed while he was still alive. (Beware of a mistaken identification of this work as the Assumption). 

In the corner here are very damaged frescoes depicting the Crucifixion, Resurrection with the Women at the Tomb, Christ's Descent into Hell and the Marriage at Cana.

Further along on the left hand side is a spirally fluted ancient column embedded in the wall, and then come some more 11th century frescoes. The first shows what is thought to be SS Giles and Blaise.

This is followed immediately by one that depicts the legend of St Alexis, a 4th century hermit. According to this, he was a young nobleman who left home and went to the East to live as a hermit, but then returned to Rome. His parents did not recognize him, and he took a job as their servant and lived under a set of outside stairs. After his death, it was noticed that he clutched a piece of paper in his hand. It was impossible to open his hand, and in the end the Pope came and succeeded in doing so after bestowing a blessing. The paper proved who he was, and in the picture you can see his parents struck with grief and his wife kissing him.

Above this fresco is the lower part of one depicting Christ with angels and saints. These are tentatively identified as (left to right) SS Nicholas, Gabriel, Michael and Clement.

At the portal into the left hand aisle are fragments showing St Anthony of Egypt and Daniel in the Den of Lions.

Finally on the left hand wall is a fresco showing the Legend of Sisinnius, the husband of a Christian woman, in two panels. The top one shows him being disrespectful in church while Clement is saying Mass, and being struck blind. The lower panels shows his sight returning at home at the prayer of Clement. However, he still orders his guards to arrest the pope. They start hallucinating, and instead grab a column lying on the ground.

The most interesting thing about the painting is not the pictures, but the text in the lower part. It's one of the oldest surviving examples of the written Italian language, distinct from the Latin from which it derives. Incidentally, what is written is Sisinnius's comment on the matter, so the first written Italian that we have is an expression rather unfitting for a church: Falite dereto colo palo, Carvoncelle. Albertel trai, Gosmaris, fili dele pute, traite meaning "Carvoncel, get behind with a lever. Pull, Albertel and Gosmar, pull you sons of whores". Clement, being respectable, speaks in Latin: [Propter] duritiam cordis vestris, saxa traere meruistis meaning "Because of the hardness of your heart you deserve to pull stones". Unfortunately, the fresco has faded badly in patches and the texts are not now easy to make out.

Above this fresco is the lower part of another one showing St Clement being enthroned as pope by his three predecessors, SS Peter, Linus and Cletus.

Quite extensive remnants of the original floor can be seen. This was made out of fragments of polychrome marbles, arranged in a semi-random way to form geometric patterns. The quality of the work is very poor compared to the floor of the church above.

To the right of the altar is a doorway which lets you into the void between the supporting wall of the apse above, and the original apse of this lower church. There is a way through here to the other side of the wall running longitudinally through the central nave, where you find yourself in the right hand part of the nave which gives the mistaken impression of another side aisle. When going through this short passage, if you look up you will see a memorial to Amleto Giovanni Cicognani who was cardinal here until his death in 1973. Three modern bronzes form a Calvary.

On the left, immediately on entering this part of the nave (to the right facing the apse), is a recently restored fresco described in guidebooks as being of Limbo. It is actually a scene traditionally referred to in English as the Harrowing of Hell. The teaching is that, after Christ's death on the Cross, he went down to Hell to take up to heaven the righteous people who had died before him. The figure on the right is Adam (Eve has been lost). Christ treads on a devil; behind him is a figure of an Oriental (Syrian?) monk holding a Gospel book. The fresco might have been part of a memorial to this anonymous monastic.

Left hand aisleEdit

Some fresco fragments at the entrance to this aisle from the narthex are too far gone to be identifiable.

A circular cavity here was thought by the original excavators to have been a baptismal font, but further examination suggests that it may instead have been part of a forge where church bells were made. This hypothesis has been supported by recent excavations beyond the end of this aisle, which have uncovered a real font in a baptistery.

At the entry to the stairs leading to the Roman house below the church there is an altar to St Cyril, believed to be over the remains of a shrine containing his relics. There are many plaques donated by Eastern national Churches in gratitude to their apostle, as well as a modern mosaic of him. Most of the modern Slavic nations are represented, as well as the Moravians who are now counted as Czechs.

In the far left hand corner are remains of 10th century frescoes depicting monks, the Crucifixion of St Peter and a saint identified as perhaps St Cyril.

Now, go down the stairs here into the ancient Roman remains.

Ancient Roman remainsEdit


At the bottom of the stairs to the right, there is the entrance to a very narrow alleyway which runs under the junction between the nave and apse of the church above. It separates two completely different structures, both dating from the end of the 1st century. To the left, under the apse, is a building which was converted into a Mithraeum or a temple of the mystery religion of Mithras. To the right is a large building under the nave of the church, of which only part of either side has been excavated. The original excavators, indulging in wishful thinking, identified this as the house or palazzo of St Clement, but it was certainly not a private house.

There have been a very few traces found of a further, fourth layer of occupation below these two structures. These seem to have been private houses of the Republican period before Christ, destroyed in the great fire of the year 64 that cleared the way for the Domus Aurea of Nero. It seems fairly certain that the site then formed part of the enclosure of that enormous palace, with possible ancillary buildings.


On reaching the bottom of the stairs, you bear left to enter the Mithraeum.

This building to the west of the alleyway is slightly wider than the church on top (32.5 metres), and built entirely of brick. Stamps on the bricks give a date of 90-96 AD, when it replaced another building which itself was probably a repaired survivor of the AD 64 fire subequently incorporated into the Domus Aurea. 

The complex originally consisted of a central barrel-vaulted hall surrounded by a corridor, and four large rooms to the east next to the alleyway. Two of these have surviving stucco vaults, and to the south a large stairway led to an upper floor. There is evidence of a third storey. The hall vault was pierced by windows, indicating that there was probably an open courtyard on its roof.

The original function of this building is very obscure, but a reasonable surmise is that it had something to do with the activities at the Colosseum nearby. Whatever it was, it was converted around the year 200 into a Mithraeum. The central hall became the temple, and this was provided with a free-standing altar. On its front is a relief of the god Mitras slaying a bull, and on the sides are representations of two torch-bearers called Cautopates and Cautes in the mythology. A niche for a statue of the god was inserted into the far end of the room, and longitudinal stone benches provided down the sides. The vault was decorated with stars.

The furthest from the stairs of the ancillary rooms is described as a schoolroom, because it also has stone benches against the walls. It could have functioned as a place for lectures, sermons and rituals. A precious fresco fragment here of the 3rd century depicts a worshipper (?).

Under the churchEdit

The eastern building (the one under the church) displays a complex history, and requires careful analysis. As mentioned, the idea that it was a private house is now discounted. Also now considered significant is that no evidence of any Christian activity was found here, not even a graffito.

The width of this building is exactly 100 Roman feet or 29.5 metres. Its length is unknown, since its other end has not been excavated. However, it is thought that it ran as far as the present Piazza di San Clemente because there used to be an ancient street there.

The western end wall next to the alleyway demonstrates that the external walls of the edifice were built out of large blocks of tufa, the so-called opus quadratum style which was very archaic at the time of the building's erection at the end of the 1st century. This is taken as good evidence that the building had a special function which required extra security -not a house. There is no entrance here, nor on the excavated side walls, so it is also thought that there was a single entrance at the east end for the same reason. This rules out the theory that the building was a horrea or warehouse.

The interior of the building consists of a series of rooms opening off a central courtyard (the latter is unexcavated). The rooms at the west end are much smaller than those to the north and south. The chambers are partitioned off and lined by walls in opus quadratum, made up of little square stone blocks laid in a diaper pattern, and ordinary brick which the Romans called opus latericium. The style where the two are used together, as here, is called opus mixtum. The ceilings are barrel vaults in concrete. The rooms on the north and west sides have communicating side doors, but those to the south that have been excavated do not. You pass through these northern rooms to reach the exit back up into the basilica.

At the end of the excavated area on the north side is evidence of a stairwell, so there must have been an upper storey. Further, the rooms have beam holes which indicate that they were divided into lower and upper chambers by wooden floors in the first phase of the building.

In probably the 2nd century, the building was modified. The floors of the rooms were raised by 80 centimetres (the courtyard was left alone), the wooden insert floors were removed and the interior walls were thickly plastered (opus signinum). 

After the middle of the 3rd century there was a much more radical restructuring, which some have suggested is evidence of conversion into a Christian church (the evidence for this does not exist). The rooms and the courtyard were filled with rubble, and the upper storey apparently rebuilt or remodelled. When the basilica was built, some of the fabric of this edifice was incorporated into the new structure. The configuration is not sufficiently clear to distinguish whether the new structure involved a radical change of function.


What was this building? The very strong outer wall and lack of entrances, as mentioned, suggests that the activities inside were a security issue which influenced the architecture.

A plausible suggestion is that this was the moneta or imperial mint, where the empire's coinage was struck. It is known that this was in the vicinity of the Colosseum, and epigraphs to various gods by employees of the mint have been found nearby. The date of its establishment in this area is known from documentary sources to have been around the end of the 1st century, which accords with the archaeological evidence. 

Further, it is known that the mint workers went on violent strike in 274 and were massacred, which might tie in with the building's reconstruction at about that time. Coin production is known to have been suspended for a period.

However, the moneta hypothesis lacks direct archaeological evidence of the making of coins on the site. Hopefully, possible further archaeological investigation might settle the issue of what this building was.


After passing the Mithraeum and making your way into the rooms on the south side of the possible moneta, you can hear water rushing by. The sound comes from a spring feeding into the Cloaca Maxima, the great sewer that helped to drain the area of the Roman Forum. Funnily enough, some tourists drop coins into it, taking the spot for a wishing well. 

When this level was first excavated, water seepage proved a serious problem and prevented people from visiting. Descriptions at the start of the 20th century mention the Mithraeum being occupied by standing water. To solve this, in 1914 a project was put in place to tap the spring causing the inflow and to direct its course into the Cloaca Maxima via a new pipe. This was successful. The water is suprisingly clean and pure, and has been used by the convent in the past (not now) for domestic purposes.


In the 1930's, a small catacomb with sixteen loculi was discovered just north of the possible moneta, below the staircase by which you first entered the lower church from the shop. At that point, you might have noticed a grating in the floor opening into this catacomb. Another view is available through an iron gate, just before you reach a second set of stairs which provide you with the exit to this level.

Because the catacomb is within the city walls, something prohibited by ancient Roman law, it is dated to the 5th or 6th centuries and hence was the old church's cemetery (an alternative date of around AD 700 has been argued for).

5th century baptistery Edit

Matilda Webb in her The Churches and Catacombs of Early Christian Rome 2001 has this:

"The recent discovery here of a 6th century baptismal font demonstrates that more is yet to be unearthed. The font, of polygonal form with a circular interior, 2 metres in diameter, is revetted with white and green marble plaques in a stylistic representation of waves."

She does not give a footnote reference, and the writer has not been able to trace the write-up of this excavation. Having asked around, the consensus is that she muddled her notes and that this paragraph actually refers to Santa Cecilia .


Opening times for visitors (including the scavi) are:

Weekdays, 9:00 to 12:30, 15:00 to 18:00.

Sundays, 12:15 to 18:00.

If you see the doors open earlier or later than these times, it is becase a Mass is being celebrated. You are not welcome to visit the church during Mass, unless you wish to attend it.

The scavi have an admission charge of ten euros; tickets can be bought in the shop. Unlike in the catacombs, you can look around by yourself without a guide to supervise. On the other hand, this means that the rooms of the Mithraeum are gated and are only viewable from the doorways by ordinary visitors.

The church has a policy of not allowing any photographs. Please buy the postcards etc if you want pictures. The staff can be serious about this.

Note that the popularity of the church means that it is worked by beggars. When it is opened in the afternoon, you may have one of them pretending that there is an admission charge or donation.


The feast of Pope St Clement I is celebrated with great solemnity on 23 November, as is the feast of SS Cyril and Methodius on 14 February. The feast of St Alexis is on 17 July, and that of St Servulus on 23 December.

Mass is celebrated (church website, May 2019):

Weekdays at 8:00 and 18:30;

Sundays and Solemnities at 9:00 and 11:00. The language used is Italian. Also, a Mass in English at 10:00 on Sundays.

On Mondays to Fridays the Rosary is recited at 18:00, before Mass.

Confessions are heard before Masses.

Unlike a lot of other churches in the Centro Storico, the friars here do not do weddings.

External linksEdit

Official diocesan web-page

Italian Wikipedia page

Church's website

Tour on church's website, with downloadable pocket guide to excavations

Nolli map (look for 30)

Kunsthistorie gallery (very large, good for the mosaic)

Online-utility slideshow

"De Alvariis" gallery on Flickr web-page with gallery

Conoscere.libello web-page with good photos

Roma SPQR web-page with gallery gallery

"Romeartlover" web-page

Info.roma web-page

"Sacred-destinations" web-page (English)

"Romaincamper" web-page

"Tesoridiroma" web-page

List of cardinals

"New Liturgical Movement" blog; photos of lower basilica on mithraeum

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