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Santi Cosma e Damiano is an ancient church and minor basilica located on the east side of the Roman Forum in the historic rione Monti, and has the postal address of Via dei Fori Imperiali 1. Pictures of the church at Wikimedia Commons are here. There is an English Wikipedia page here.

The dedication is to two Greek brothers named Cosmas and Damian who were doctors, martyrs and saints.


This church has a complicated architectural history, which affects its present access arrangements. It was made up of two ancient Roman buildings, which had completely different functions and which belonged to two separate architectural ensembles. These two formed one church for centuries, until the two original buildings were separated again in the late 19th century. They are now inaccessible from one another.

The main body of the church was formed from an ancillary building in the south corner of the temenos enclosure of the Temple of Peace, often misnamed "Forum of Peace" or "Forum of Vespasian" (it was not a forum). This occupied the south-east part of the site of the Imperial Fora, and the fabric of the church is the only part of it to survive above ground.

The entrance vestibule was formed from a circular temple in the Roman Forum, traditionally called the "Temple of Romulus" but conclusively identified by the archaeologist Filippo Coarelli as the Temple of Jupiter Stator.

It is important in the historical understanding of the church to remember that the main entrance used to be on the Roman Forum. After the mediaeval neighbourhood that used to occupy the forum was cleared in the 16th century, the forum formed a very important Christian sacred space until its excavation which began after 1870. This church occupied a central location in this. From west to east, the churches were: San Giuseppe dei Falegnami (Mamertine Prison), Santi Luca e Martina, Sant'Adriano (now the Senate House), Santa Maria Liberatrice al Foro Romano, San Lorenzo in Miranda, this church, Oratorio della Via Crucis nel Foro Romano, Santa Francesca Romana and finally the Colosseum which counts as a church in its own right -Santa Maria della Pietà al Colosseo. The archaeological excavations, undertaken for nationalist motivations, destroyed the integrity of this ensemble. In the process, the entrance vestibule of this church was deconsecrated and turned into an ancient monument.

The basilica from the Palatine with its former entrance -Basilica of Maxentius on the right.

As a result, the basilica now has a modern entrance on the Via dei Fori Imperiali where no entrance used to exist (the original monastery entrance is round the corner in Via in Miranda).


Temple of Peace[]

This was built by the emperor Vespasian and completed in the year 75, as a commemoration of his victory over the Jews and the destruction of Jerusalem in the year 70. It formed an enormous square courtyard, with its major axis north-west to south-east, in line with the Imperial Fora. The north-west had a curtain wall with a monumental propylaeum entrance, and the two sides had colonnaded walkways. The courtyard itself was occupied by a formal garden.

The temple itself was opposite the entrance, and was a simple and rather small apsidal hall with a hexastyle (six-column) frontage. It was flanked by continuations of the covered walkways (known as porticus, which is spelt the same singular or plural) and behind these were ancillary rooms or halls. One of these contained the famous Forma Urbis or Severan Marble Plan, which was the official public map of the city carved in marble on the south-western wall of the hall. This wall is still standing, to the left of the modern entrance -the rest of the hall, and all the rest of the complex, is beneath the Via dei Fori Imperiali.

The part of the complex that was used for the basilica, and hence survived, comprised two rooms behind the wall with the map on it. These were tucked into the southern corner of the enclosure. The southern room was slightly wider than the northern one, and the partition between the two used to be where the triumphal arch now is. The northern room, including what is now the apse and the sacristies behind, had its own apse which is now gone. The function of these two rooms is unclear; they may have been the temple's library or, more likely given the existence of the apse, a place for meetings and lectures.

The complex seems to have continued in use through the 4th century, but was deserted by the early 5th. It was a headquarters of the city's public medical service, and doctors on the government payroll seem to have practised here. This is circumstantial but persuasive evidence for the reason SS Cosmas and Damian were chosen as the church's patrons, since they are also patrons of the medical profession.

Temple of Romulus[]

This circular brick building was erected in the early 4th century. The bronze doors and doorcase were pillaged from some 2nd century building, and the flanking porphyry columns also came from elsewhere. The traditional identification links with a legend that Maxentius, the last emperor actually to reside at Rome, was so heartbroken at the death of his four-year-old son Romulus that he had him deified and provided this temple for him.

Some scholars doubt that it was a temple at all, but rather an audience hall. Coarelli (see p. 42 of his Rome and Environs, an Archaeological Guide) puts forward a persuasive argument that it was a rebuilding of the ancient Temple of Jupiter Stator. The building used to be flanked by two narrow apsidal halls (the one on the right is in better condition), and these may have been the shrines of the Penates or household gods whose temple had to be demolished to make way for the Basilica of Maxentius.

Foundation of the church, and early days[]

The foundation of the church was in 527, when Theodoric the Great, king of the Ostrogoths , and his daughter Amalasuntha arranged the donation of the two buildings to the Church under Pope Felix IV. Three interesting observations can be made about this. Firstly, the king was consciously not acting in his own name, but as the agent of Emperor Justinian I in Constantinople. Modern historians may have pretended that the Roman Empire came to an end in the West in 476, but the inhabitants of Rome were not aware of this fifty years later. Secondly, the area of the Roman and Imperial fora was still functioning as part of the city, and had not yet fallen into complete ruin. Thirdly, this was the first Christian church to be founded in the area. Again despite modern popular historical imagination, much of the nobility of Rome was still hostile to Christianity in the 5th century and this may have prevented the provision of churches in the cultic centre of the city before this one.

The new church was not a titulus or a monastic church, but was a diaconia. This meant that it was a centre for the Church's charitable activities such as helping poor people. When the pope united the two buildings to create a basilica devoted to the two holy Greek brothers and doctors, Cosmas and Damian, he may have been wishing to continue the free public medical services formerly based in the Temple of Peace. There may also have been a deliberate contrast with the ancient pagan cult of the divine twin brothers Castor and Pollux, who had been worshipped on the other side of the Forum in the Temple of Castor and Pollux.

The apse of the new church was decorated with a mosaic, representing the parousia (coming at the end of time) of Christ. This work was immensely influential, and art historians have been able to trace its inspiration in mosaics in later Roman churches. It stands nowadays as one of the foremost examples of the old Classical style of depiction (see the mosaic at Santa Pudenziana for an example of this) starting to mutate into the (then novel) Byzantine style.

The cult of the two doctor saints became very popular in the Middle Ages and later, and the belief grew up that any sick person who slept overnight in the church might be granted a vision of them leading to a cure. This was an obvious adaptation of the pagan tradition of the asclepeion. Pope Sergius I restored and enriched the furnishings in the late 7th century, and so did Pope Adrian I in the 8th. The latter also enriched the diaconia with landed property, in order for it to have income to feed and bathe poor people and pilgrims.

Middle Ages[]

It used to be thought that the Roman Forum was in complete ruins from the Sack of Rome by Alaric in 410, but this is false. The area functioned in civic mode until the 9th century, and it is thought that serious ruination began with a powerful earthquake in 847. Some modern scholars argue for a continued civic identity for the Forum until the sack by the Normans in 1084.

After that, for almost half a millennium, the Forum was a mediaeval Roman neighbourhood such as the more familiar ones at Trastevere or Campo Marzio . This long period of occupation by small households caused the massive rise in ground level, familiar from depictions before 1870, and caused a problem for the church since it put the front door below ground level. This issue had to be addressed in the 17th century. Formerly, scholars thought that the fill was caused by landslip and floods. There was a landslip from the Capitoline Hill in the Dark Ages, but not from the Palatine and the drainage basin in which the Forum is situated is too small for major flooding.

The hurried, slipshod and ideologically compromised archaeological excavations starting in the 1870's destroyed most of the buried evidence of the medieval Forum without record. Some small finds which caught the eye are in a room at the Crypta Balbi museum. However, still very little is known, or being researched about, concerning this half-millennium in the Forum and how this church functioned during it.

Renaissance and Baroque[]

In 1512 the church was granted to the Regular Tertiaries of St Francis (TOR), who are still in charge. This was the beginning of the modern era for the church. Back then there were no buildings attached to the church, and the first bird's eye views from later in the century show a vineyard where the convent now is.

The Sack of Rome in 1527 probably seriously damaged the neighbourhood, and gave the opportunity for clearance. In 1534 Pope Paul III ordered the demolition of two hundred houses and four churches to create a new processional route from the Arch of Septimius Severus to the Arch of Titus , then a fortified gateway to the domain of the Frangipani family. This passed through the new open space, and was given an avenue of elm trees. The first person to use this in procession was the Emperor Charles V. Unfortunately the area was found convenient for a livestock market, which survived to attract the sensibilites of romantics until the late 19th century, and gave the area the name of Campo Vaccino or the cow-field.

In 1583, the alleged relics of SS Mark and Marcellian were discovered in the church. They were originally at the Catacomba di Basileo, and how they got here and how they were identified seems to be unrecorded. They were enshrined in the crypt.

In 1632, Pope Urban VIII ordered the restoration of the basilica. The works, projected by Orazio Torriani and directed by Luigi Arrigucci from Florence, raised the floor level by seven metres. This made it level with the ground of the Campo Vaccino, thus avoiding the infiltration of water, and created two crypts at the original floor level. The old floor of the basilica is still visible in the crypt of the present church, which is actually the lower part of the original edifice. The entrance from the Forum was also raised and given a decorative Baroque pediment, and the circular entrance hall was given a cupola.

Within the main body of the church, the triumphal arch was widened and three side chapels provided on each side. So, the arch is now low and wide rather than tall and narrower as it used to be in the Middle Ages. The present carved wooden ceiling was inserted, displaying the arms of Pope Urban, and a new high altar provided.

In the same restoration the tertiaries were finally provided with a convent which was built on the vineyard adjacent, with the cloister through which you now enter the church.

There used to be a tall Romanesque campanile attached to the bottom left hand corner of the basilica, where the entrance from the cloister now is. This used to have five storeys above the roofline, and the face of each storey had two open arches. The evidence of representations before the restoration indicates that the lower three storeys had their arches blocked up in the early 16th century, presumably because the tower was unstable. This campanile was demolished to make way for the convent, and a Baroque bellcote provided instead.

Modern times[]

After the 17th century restoration, the church was left alone until the late 19th century. In 1880 the excavation of the Forum to the early Imperial ground level left the main entrance stranded, and it was then that the Baroque pediment was destroyed. The temple's entrance was lowered to its former position and, as a result, access from then on had to be through the monastery. This was sundered from its former neighbourhood to the north by the Via dei Fori Imperiali in the 1930's. In 1939 a spectacular 18th century Neapolitan crib or presepe was donated to the church, and this was housed in the former entrance vestibule.

In 1949, the alleged relics of SS Mark and Marcellian in the crypt were examined and conserved.

After the war, the archaeologists continued with the process of turning the former temple into an ancient monument. The Temple of Romulus was now regarded not as part of the church but as the best-preserved pagan temple in Rome, together with the Pantheon. A new formal entrance for the church was hence opened on the opposite side, on Via dei Fori Imperiali. The archway of this, designed by Gaetano Rapisardi, gives access to the cloister, and one turns left after entering this to find a doorway into the lower left hand corner of the basilica.

In 1990, further very controversial work was done on the temple. Arrigucci's 17th century marble floor was smashed up, hence joining the crypt to the vestibule to form one space. The crib was ejected and found a new home in a room of the cloister; it was recently vandalised and was hence withdrawn from display, but should now be visitable. The entrance was provided with stairs, hence allowing entrance to visitors from the Forum, and the interior walls scraped back to the brickwork. In the process, some 13th century frescoes were found, and these have been conserved. Finally, in 2000 a large glass window was installed in what used to be the doorway between the vestibule and the main body of the church, and hence visitors to the latter can look downward into the former.

There is little pastoral justification for the church nowadays, but it is part of the Centro Storico marriage circuit and is one of the most popular for weddings. As a result, if you visit on weekends you may find a wedding going on. Individual visitors are usually tolerated during the preparation for a wedding, but if you stand on the carpet in front of the altar in order to examine the mosaic you may find yourself being sworn at in Roman dialect.


The church remains a titular diaconate. The previous cardinal deacon was Beniamino Stella, appointed in 2014, who was raised to the rank of Cardinal-Bishop. The incumbent cardinal deacon is Mario Grech, appointed in 2020.


The original church entrance, on a quiet day for visitors.

"Temple of Romulus"[]

As mentioned, you have to visit the Roman Forum to view this. It is a cylindrical brick building, with a shallow octagonal dome having a pitched roof in eight segments. There is a narrow tiled area of roof between the drum of this dome and the roofline, and the drum itself has one step which is also tiled. On the dome is a circular Baroque lantern with eight arched windows forming an arcade and bearing a cupola in lead.

The entrance is impressive, although the architectural elements were originally scavenged from elsewhere. It was lowered back to its original position by the archaeologists, having been raised in the 17th century and put on the major axis of the church (just to the left of the present entrance). A pair of porphyry Corinthian columns on tall plinths support a horizontal entablature with a narrow blank frieze and a projecting dentillate cornice. The decorative marble doorcase has its own cornice. The original bronze double doors are a very rare survival, and incredibly the door lock still works.

To the left and right used to be two narrow apsidal halls, each having a doorway flanked by a pair of cipollino Corinthian columns. Those on the left have gone, but the pair on the right has survived and one of these bears a fragment of entablature.

As a result of the recent re-ordering the bronze doors are usually kept open during visiting hours, so that tourists can admire the mediaeval frescoes or (more usually) shelter from the sun. Hence it is difficult to get a good photo of them, but the "Romeartlover" web-page has an excellent one.


The adjacent convent is a 17th century building, and important in its own right. It has its original entrance on the Via in Miranda, which is worth looking at. The rusticated Baroque arched doorway is topped with a cornice in curlcues, and within this is a capsule-shaped plaque bearing the emblem of the Tertiaries. You can see the crossed arms of Christ and St Francis bearing wounds on the palms, the Crown of Thorns and the Nails of the Passion. If the main entrance is closed for some reason, this is the entrance to use.

Next to the new entrance to the complex the convent has rooms with the original marble floor of the Forum of Peace, and the wall to the left of the entrance is where the 150 marble slabs of the Forma Urbis Romae were originally hung. The entrance itself is a neo-Romanesque work of 1947, in the form of an elongated triumphal arch in travertine stone. A pair of gigantic derivative Doric pilasters with exaggerated capitals flank the arch, and above is a blank wall bearing the name of the basilica.

To the left of the entrance, the Baroque campanile can be seen peeping over the convent building. It has three arches for its bells, a small one over two larger ones. The former is in the form of a minature triumphal arch, with a triangular pediment and sweeping sides.

The entrance opens into the cloister, which is a cool spot with simple architecture. The frontages are in pink with vertical and horizontal white bands. The arcade arches have imposts below their intradoses, but no other decoration. The courtyard is paved in cobbles, with an X in irregular paving slabs meeting at a Baroque fountain embellished with sculptures of horses. The basin contains goldfish.

The entrance to the church is in the top left hand corner, and by this are anonymous 17th century wall frescoes in the cloister walk. These depict scenes from the lives of Franciscan saints. You passed another fresco, of St Francis receiving the stigmata, when you entered the cloister.

Main body of church[]

You can see the right hand outer wall of the church if you visit the Forum, as well as the nave frontage above the "Temple of Romulus" which has a row of three large arched windows. Otherwise the fabric is concealed by the convent, and is invisible from the Via dei Fori Imperiali. The plan is almost square, with the large semi-circular external apse itself concealed within curtain walls of the convent structure.


"Temple of Romulus"[]

There is not much to see in here now, except bare brick walls and the conserved 13th century frescoes. The archaeologists scraped off all the 16th century stucco to reveal the brick, which is historically dishonest because the brickwork would have been stuccoed in ancient times, too.

The frescoes were commissioned by Pope Urban IV, and are important because they display a style known as popolaresco which was intermediate between the old Byzantine style and the later, more naturalistic styles such as the Mannerist.

There is a well beneath the floor, which is thought to be related to the cult of healing associated with the patron saints during the early history of the church. It would have functioned as a holy well, with the water being used for ablutions and drinking in hope of healing. The fascinating thing about this is that it indicates the old temple was taken over as the asclepeion or healing shrine, rather than merely the entrance vestibule to the church. If so it was the most important part of the church in the Dark Ages, and the basilica was simply the liturgical annexe where Masses were said.

Layout and fabric of basilica[]

Santi Cosma e Damiano floor plan.png

The present plan of the basilica was designed according to the norms of the Counter-Reformation: a single four-bay nave, with three external chapels on the left hand side and four on the right. These are entered through large arches, above which are fresco panels. The first bay of the nave has the modern entrance on the left hand side, where a chapel would perhaps otherwise be.

The frescoes on the nave walls and in the chapels are as a result of the 17th century re-ordering, except for one which is 13th century.

The sanctuary occupies the apse. To the left, behind the triumphal arch pier, is a short passage leading to the crypt stairs. In the left side of the curved apse wall is a doorway piercing the wall, which leads into the sacristy which is a long, narrow rectangle on a transverse axis.

The large apse now looks quite oversized, because of the reduction in the height of the church interior caused by the 17th century restoration. It contains the choir stalls of the tertiaries, set against the curved wall. The apse is framed by the triumphal arch, also altered by that restoration and now having an elliptical profile. Its mosaic was mutilated in the process.

The frescoes on the walls and on the ceiling are mostly anonymous works of the 17th century. The ceiling itself is a finely carved and gilded flat wooden affair, with a rather bad central fresco of the two saints in heaven. It is flanked by a pair of shields showing the Barberini bees, since Pope Urban VIII belonged to that family.

The basilica of Santi Cosma e Damiano

Apse mosaic[]

The mosaics are masterpieces of 6th century ecclesiastical art. The apse mosaic is especially fine, but you need to remember that you should be standing seven metres lower than you actually are, in order to see it as the creators intended. There is a coin-operated light for it at the head of the center aisle in front of the alter.

In the middle is Christ at his parousia, or Second Coming as triumphal judge at the end of time. He is standing on the red clouds of dawn, and is dressed in golden robes with a single monogram I which stands for either Iesus or Imperator. In his left hand he holds the rolled-up scroll of the Torah, which only he is able to interpret. To the left is St Paul, and to the right is St Peter. They are introducing SS Cosmas and Damian to Christ, and it is not possible to tell which is which because the mosaicists followed the tradition that they were identical twins. They are carrying martyrs' crowns. To the far left is Pope Felix IV, who as founder holds a model of the church; this figure was restored in the 17th century. The reason for this is that Pope Gregory XIII saw fit to alter the figure to show Pope Gregory the Great in the previous century, and a very bad job was done. The Baroque restorers put it right. To the far right is the martyr St Theodore. The figures stand in front of a river labelled Iordanes (Jordan), and are flanked by palm trees. Note the phoenix on the left hand palm, a symbol of the resurrection.

Below Christ is another representation of him, this time as the Lamb of God accompanied by twelve sheep representing the Apostles. The Lamb stands on a hill with Jerusalem on the left and Bethlehem on the right, and from the hill flow the twelve Rivers of Paradise labelled Gion, Pison, Tigris and Eufrata (Euphrates).

Below the Lamb is the dedicatory inscription. It reads:

Aula Dei claris radiat speciosa metallis, in qua plus fidei lux pretiosa micat. Martyribus medicis populo spes certa salutis, venit et ex sacro crevit honore locus. Optulit hoc Domino Felix antistite dignum, minus ut aetherea vivat in arce poli.

(The beautiful hall of God shines with metals, in which the precious light of faith shines the more. A certain hope of salvation comes to the people through the doctor martyrs, and the place increases in sacred honour. This thing Felix brought to the Lord, unworthy [of being] the high-priest, so that he may live in the ethereal citadel of the Pole [of the heavens].)

Triumphal arch mosaic[]


The mosaic on the triumphal arch was part of the same scheme as the apse mosaic, but may have been completed later in the time of Pope Sergius I at the end of the 7th century. The composition is derived from the first chapters of the Book of Revelation. It focuses on the reclining Lamb of God, on a throne with a cross above and the Scroll with the Seven Seals below. The Lamb is flanked by seven candlesticks representing the Seven Churches of God, and also four angels. In the upper corners are, to the left, a winged man (not an angel) representing the Gospel of Matthew, and to the right the eagle of the Gospel of St John. Above the arch pilasters can be seen arms stretching upwards to the Lamb. These belonged to the twenty-four elders of Revelation; the rest of them, and the other two symbols of the Evangelists, were lost in the Baroque re-ordering.


Below the apse mosaic, you will see a set of tondi showing Franciscan saints painted in about 1635. The men are on the left, and the women on the right. Bizarrely St Brigid of Sweden was included, and this caused offence because in no way was she a Franciscan, but had founded her own order of the Bridgettines.

The ornate Baroque high altar is by Domenico Castelli of 1637, and has a 12th century icon of Our Lady as the altarpiece. The painting of the ceiling, done in the major re-ordering, was by Marco Montagna. 

There is a fine paschal candlestick to the right of the altar, consisting of a twisted marble column.

Side chapels[]

The seven chapels are as follows. They all used to have frescoes on their side walls and on their barrel vaults.

The first on the right used to be dedicated to Our Lady of Sorrows, with an altarpiece showing the Deposition by "Giovanni Roos" (Jan Roos?). The frescoes on the side walls were by Giovanni Battista Speranza, except for a 13th century one depicting Christ the Crucified King. This chapel has been restored, and this mediaeval fresco is now the altarpiece. The side walls have been scraped clean, which is a pity. Under the altar is a fluted pillar capital in porphyry -a very impressive piece of ancient stonework, as the rock is very hard.

The second on the left is dedicated to St John the Evangelist, with paintings by Giovanni Baglioni who was buried here. The altarpiece has suffered serious damage from damp.

The third on the right is dedicated to St Anthony of Padua. The altarpiece is by Spadarino. It shows the saint having a vision of the Christ-Child while reading the Scriptures; his original doctrine was that the believer can encounter Christ by reading any part of the Bible (an important idea lost in later sentimentality).

The fourth on the right is dedicated to St Francis of Assisi, and the altarpiece is of the school of Girolamo Muziano.

The third on the left is dedicated to SS Rose and Rosalia, and the anonymous altarpiece of the early 16th century shows them.

The second on the left is dedicated to St Alexander. The altarpiece is a Crucifixion in the style of Rubens, but the frescoes on the side walls showing scenes from the saint's martyrdom are by Francesco Allegrini.

The first on the left is dedicated to St Barbara, and has especially good stucco work. The frescoes on the side walls are by Allegrini.


The sacristy preserves some old church plate, notably a small Cosmatesque ciborium of the 13th century, an 11th century reliquary of St Matthew and a medieval chalice.

The altarpiece of the altar here is The Good Samaritan by Speranza.


The crypt of the basilica has the original floor level of the church. Some Cosmatesque remnants are visible in the floor. The alleged relics of SS Mark and Marcellian are enshrined here, as well as (apparently) a portion of those of the patrons SS Cosmas and Damian.


The church should be open daily from 10:00 to 13:00, and 15:00 to 18:00 (church's website, 2017). If you find the main entrance closed, try the old monastery entrance. The same times apply to the crib.

The crypt may be visited, but only on prior notice. Phone 00 39 06 692 0441 to arrange this (2016).

The "Temple of Romulus" is only accessible on paying the entrance fee for the Forum and Palatine archaeological site.


Mass is celebrated:

Weekdays 7:30, Sundays and Solemnities 11:30.

The crypt


  • Apollonj Ghetti, B. M: Nuove Considerazioni sulla Basilica Romana dei SS Cosma e Damiano. Rivista di Archeologia Cristiana 50, 1974.
  • Coarelli, Antonio: Rome and Environs, an Archaeological Guide. University of California, 2007.
  • Flaccomio, G. et al: Il "Tempio di Romolo" al Foro Romano. Quaderni dell' Instituto di Storia dell' Architettura 26, Sapienza, Rome, 1980.
  • Iamurri, L: Santi Cosma e Damiano. Roma Sacra 3, 1995.
  • Matthiae, G: Pittura Romana de Medioevo Vol 1, Secoli IV-X. Rome 1987.
  • Roma Archeologica: Le Chiese Paleocristiane di Roma, Rome 2003.
  • Touring Club Italiano: Roma, 2004, pp. 276-277.
  • Watkin, David: The Roman Forum. Profile Books, 2009.
  • Santi Cosma e Damiano at (website closed, all content moved to this wiki)

External links[]