Churches of Rome Wiki

San Carlo alle Quattro Fontane is a 17th century convent church at Via del Quirinale 23, which is in the rione Monti. Pictures of the church on Wikimedia Commons are here. There is an English Wikipedia page here.

The dedication is to St Charles Borromeo.


This is one of two small Baroque churches close together on the ridge of the Quirinal Hill, the other being Sant'Andrea al Quirinale. Together they are now recognized as being one of the great architectural experiences of Europe, and attract many discerning visitors from worldwide.

The two churches are a pair of complementary masterpieces by the two titanic rivals of the architectural world of 17th century Rome, Francesco Borromini and Gian Lorenzo Bernini. The personalities of these two geniuses are reflected in their respective churches. Bernini was the talented son of a successful society sculptor, brought up to be sophisticated and self-confident, and his church of Sant' Andrea is his exercise in Baroque as theatre. Borromini had a difficult upbringing and struggled with mental illness (he eventually committed suicide), but his neurotic reclusiveness masked a brilliant analytical mind and his church of San Carlo is his demonstration of Baroque as mathematics.


The formal dedication of the church is jointly to the Holy Trinity and St Charles Borromeo, and this was the first church in Rome dedicated to the latter saint who had been canonized in 1610. The four fountains in the name (Quattro Fontane) refer to the ones which sit at the corners of the intersection where the church stands.

A long-standing local nickname for the church is San Carlino, which literally means "Little Saint Charles" after the small size of the edifice. This helped to distinguish it from the other two churches in the Centro Storico dedicated to St Charles: San Carlo ai Catinari and San Carlo al Corso (he now also has a modern parish church dedicated to him, San Carlo Borromeo). Surprisingly, the Diocese has now adopted the nickname officially; in the past such nicknames were not recognized, because of a possible insult to the saint concerned. St Charles was not a dwarf.



The church belongs to a convent founded by Spanish Discalced Trinitarians. The Trinitarian order of friars was founded near Paris at the end of the 12th century by St John of Matha, and its purpose was the ransoming of Christians taken prisoner by Muslim pirates and slave-raiders as well as during wartime. These people would otherwise have ended up as slaves, with no access to the sacraments. The saintly founder ended up dying in the convent at Rome that he founded, San Tommaso in Formis.

The emblem of the order is a Greek cross, formed by putting a red vertical bar over a blue horizontal one. This emblem influenced aspects of the church's design, as well as appearing in decorative features.

The order prospered in the context of Christian-Muslim conflict on land in Iberia, and also in the western Mediterranean where predatory shipping from North Africa roamed even until the 19th century when the Maghreb was conquered by France. However, it sank into some decay during the 15th century before experiencing a surge of enthusiasm for reform towards the end of the 16th. This was in response to the Reformation. Two main reform tendencies established themselves, in France and in Spain. The latter branch was founded by St John Baptist of the Conception, and was approved in 1599. It became known as the Discalced Trinitarians because the friars wore sandals rather than shoes ("discalced" is from the Latin discalceatus which means "shoeless" not barefoot -although the modern Italian scalzo does mean the latter). The present-day Trinitarian order, which is in charge of the church, descends from this.

By this century, the nationalist hatred between the French and Spanish was such that the reformed Trinitarians in the two countries did not co-operate very well if at all. In Rome, the Spanish Discalced founded a convent here at San Carlo and the French Trinitarians founded another, just down the road towards Santa Maria Maggiore at San Dionigi Areopagita (now demolished). Perhaps if they had pooled their resources and built one large convent instead of two little ones, Borromini's masterpiece would never have been erected.


The Spanish Discalced Trinitarians set about founding a house at Rome at the start of the 17th century, and chose a site on the summit of the Quirinal. Here they built a little temporary chapel with one altar dedicated to St Charles Borromeo, and opended it in 1612. This was only two years after the saint had been canonized. The altarpiece of this chapel is now kept in the sacristy.

However, money was a very serious problem for the friars as they tried to continue the project. They eventually found a patron in Cardinal Francesco Barbarini, who was just starting his massive scheme to build a family palazzo nearby -Palazzo Barberini.  He promised (falsely) to pay for the project, and so in 1634 (22 years after beginning) the friars commissioned the young architect Francesco Borromini. It was his first major commission in Rome, and he was to be responsible for the design of the entire complex. This was a brave move on the part of the friars, because Borromini was still an unknown despite having twenty years' experience in working for other people in the building and architectural professions. One important factor was that Borromini volunteered to work for no fee as long as he was allowed a free hand -he saw the project as an advertising campaign for his career.

The dedication to St Charles Borromeo is interesting in this context. Milan, where the saint had been the apostolic administrator of the archbishopric, was at the time ruled by the Spanish and so the Spanish Trinitarians had a national link with him. Also Borromini had been working on Milan Cathedral when St Charles was in charge, and was so impressed by him that he changed his surname from Castelli to Borromini in homage. He might have been attracted to the project by the dedication.


The Trinitarians came to the Quirinal when the area had already changed from being nothing but vineyards, to ranking as a suburb. The Palazzo del Quirinale had been begun in 1583, and the Strada Felice was cut through the area between Santa Maria Maggiore and Santissima Trinità dei Monti on the orders of Pope Sixtus V.  He also commissioned the Quattro Fontane where that road crossed the Via Pia (itself a new road, finished in 1565 to the Porta Pia), and these were completed in 1593. In other words, the fountains were there before the church was.

The site of the convent was occupied by two newish houses, which the friars had bought and demolished in 1612. This left an awkward trapezoidal plot, since the two roads did not cross at a right angle. The crossroads angle at the convent is oblique. Further, the limited funds available meant that Borromini was not going to have access to the usual polychrome stonework and gilding options for interior decoration, which meant that the form of the internal design was paramount. This accorded with his preference, and the result was a work of genius.

The convent and church began quickly, but took a long time to finish. Fortunately, the friars were careful to preserve the paperwork and we have good documentation in their archives. One of the friars, Fra Juan de San Buenaventura, wrote a surviving description of progress in 1665, the Cronaca del Convento e della Chiesa di San Carlo.

Borromini began work on the main convent block immediately, and this was inhabitable by the friars in 1635. Then the  cloister and the block fronting the Via del Quirinale was completed in 1636 (Borromini altered the frontage of the latter in 1662. In 1638 the church was begun, and work on it continued until 1641 when it stalled. Borromini erected a temporary campanile in 1643, but the money had run out and work stopped before the façade was begun. The friars decided to consecrate the unfinished church in 1646 and wait on events.

They were able to begin again only after another 22 years. In 1665 Borromini began the façade, but committed suicide in 1667. His nephew, Bernardo Castelli Borromini, continued work using his uncle's plans, firstly building a permanent campanile in 1670 and then beginning the façade in 1674. This was finished structurally in 1677, and the last sculptural decorations were finally completed in 1682. The decorative scheme was never actually finished.

The project to found a Roman church and convent had taken the friars seventy years. It had cost them a total of 11 678 scudi. The scudo was a gold coin of about 3.3 grams, and so the cost was 38.5 kg of gold or US$ 1 751 750 (June 2013 prices). This was seriously cheap for the time, even if Borromini had worked for free.

According to the story, Borromini wished to be buried in the church but the friars had scruples about interring a suicide victim and refused permission. This seems to be a myth, since his will specified that he be buried at San Giovanni dei Fiorentini, where he had been working and where his tomb is to be found. It remains possible, of course, that he was thinking about a tomb here when he designed the crypt in 1638 -an empty, unused chapel is pointed out as his intended resting place.

Subsequent history[]

The friars were very happy with the result, which was an immediate architectural sensation. The superior of the brethren reported that many educated visitors to Rome tried to obtain copies of the plans. However, this adulation only lasted as long as the Baroque style remained in fashion -until the latter part of the 18th century.

In 1710, the friars managed to extend the convent. Their refectory or dining hall was behind the church and very cramped, so they bought the house next door on that street in 1705 and built a new block containing a better refectory on its site. The old refectory became the sacristy, which it still is. The architect was Alessandro Sperone.

Subsequent history was uneventful, until the end of Papal government in Rome in 1870. The friars were misguided enough to install an organ over the entrance in 1855, destroying the fresco there.

The freehold of the convent was sequestered by the Italian government in 1873, together with those of all the other convents in Rome, but the popularity of the church among the citizens ensured that it was preserved and that the Trinitarians remained in charge. All the other convents between the Piazza del Quirinale and Santa Susanna were closed and their churches demolished, except for Sant'Andrea al Quirinale and Santi Gioacchino e Anna alle Quattro Fontane (now deconsecrated). The lost neighbouring churches were: Santa Maria Maddalena al QuirinaleSanta Chiara al QuirinaleSanta Teresa alle Quattro FontaneIncarnazione del Verbo Divino and San Caio in Via Porta Pia. The result was that a continuous line of convents was replaced by gardens and government offices in the main.

The floor of the church was re-laid in 1898, using money provided by a Basque widow lady from near Castro Urdiales in the Basque Country, Spain.

Oddly, the church became neglected in the early 20th century. Pilgrimage guidebooks of the period could get away with not mentioning it at all. The situation got worse as the century progressed, when the style of the church fell completely out of fashion and "architects" and "archaeologists" were "restoring" old churches to show naked brick walls never previously seen in such a way. Georgina Masson, in her guidebook of 1965, reported that the church was rarely open and so advised visitors at the convent to make an appeal to be let in. Further, the fabric was allowed gradually to fall into a state of serious disrepair which was causing concern at about the same time. 

This situation has subsequently changed completely, as a result of a thorough and systematic restoration which was started in 1988 and finished in 1999. Nowadays, the church is one of the more popular destinations for educated visitors to Rome. As a result, its online profile is good.


Layout and fabric[]

As mentioned, the layout of the convent is cramped and it is not possible to see the external walls of the church from the street apart from the façade and a glimpse of the dome. The fabric is in brick, rendered in stucco, except for the façade which is in travertine limestone.

The church, as expected, has a complex plan based on an oval or quasi-ellipse (the central dome) within a chamfered rectangle (the main floorspace) within an incurved rhombus with rounded corners (including the apse of the main altar, the two side chapels and the entrance area).

The quasi-ellipse mentioned is a complex closed curve formed by tracing around two identical circles touching at a point and connecting them by a pair of identical tangential circular arcs. Hence, it is not a true ellipse -in English it is called an oval although confusingly this word also refers to an egg-shaped curve. The latter use is preferred by mathematicians, the former by artists and technical drawers. 

The plan and proportions of the church are said to be based on one of the piers supporting the dome of St Peter's, but this is incorrect and derives from an 18th century comment that the entire church could fit into the footprint of one of those piers. Many writers have repeated this allegation since. Each of the piers at St Peter's is 18 metres thick, or about 324 square metres. The church's floorplan is quoted as being about 750 square metres. Always check your factoids.

From the street, starting from the west on the Via del Quirinale, the layout is as follows: Firstly, the cloister block. This has a symmetrical three-storey frontage, with a monumental entrance. Over the doorway is a tondo containing a mosaic of Christ enthroned between two liberated slaves, one black and one white. This is protected by an omega cornice (Ω) which is splayed outwards on two curlicue brackets -a typically Borrominian touch. Above this is a shield supported by two angels, and displaying the Trinitarian cross mentioned above. The entrance leads via a passage through the block to the cloister.

Then comes the façade of the church and then, on the corner, the campanile over one of the four fountains. This faces diagonally into the crossroads, and Borromini had some difficulty with the design. The result is not satisfactory, as the campanile frontage clashes with the church façade.

Around the corner is the frontage of the oldest block of the convent, again in three storeys with elliptical cellar windows

Detail of exterior, showing the Trinitarian symbol.

by the pavement. The Trinitarian cross is again prominently displayed on the symmetrical façade, which conceals the fact that this wing has a narrow wedge-shaped plan so as to assimilate the oblique angle at the road junction. The cross symbol is within a rayed glory, and is protected by a string course bending into a semi-circle to give the omega motif already seen on the main convent façade.

The cloister has a side wall of the church on the east side, and the wall of the neighbouring convent of Santi Gioacchino ed Anna on the west side. The south side has the major wing of the convent, which is four storeys and runs behind the church under a pitched and hipped roof as high as the base of the dome drum. The church apse is incorporated into it. South of this wing in turn is the little convent garden, which survives.

Finally, further down the Via delle Quattro Fontane is the rather bland 18th century annexe.


The dome is not easily visible from the street. It has an oval drum with four octagonal windows, two on the minor axis and a pair on the major axis. These give the concealed lighting to the interior dome. On top of the drum the lantern stands like a little temple or mausoleum on three concentric steps; it is again oval, and has four pairs of Doric columns with a little narrow round-headed window flanked by each pair. The pairs are separated by larger such windows, four in total, and support a cog-wheen entablature. On top the lantern ends in four concentric steps and a very large ball finial. (There is a photo of the dome on the "Romafelix" web-page in the "External links".)


The campanile stands over one of the Quattro Fontane on the outside, and the spiral staircase down to the crypt on the inside. As mentioned, the juxtaposition between the façade and the chamfered corner here is perhaps the least satisfactory part of Borromini's design and the cornice of the façade interferes with the campanile.

At ground level is the fountain basin, behind which is a large arched niche containing a relief of a figure reclining under a tree with a wolf in attendance; this is thought to be a personification of the Tiber river. Above in turn is a rectangular window with a little triangular pendent raises over a wreath motif, then the Trinitarian cross again in a heart-shaped tablet embraced by the wings of an angel, and finally the campanile itself. This is on an incurved square plan, and has two pairs of Doric columns on each face supporting an entablature with rosettes and triglyphs on the frieze. The soundholes are large rectangular voids between the inner pairs of columns. Above the entablature is a trapezoidal plinth, and finally an incurved truncated pyramidal spire in lead with a gilded ball finial.



The travertine façade was completed between 1670 and 1680 by Borromini's nephew, Bernardo, to his uncle's design. It is integrated with the monastery block to the right and the campanile to the left, but as a piece of design is self-contained. It should ideally be facing a piazza, but unfortunately has to make do with a narrow, busy street. Watch the traffic when looking at it or taking photos; visitors have been injured here.

Carlo alle Quattro Fontane.jpg


There are two storeys, and three vertical zones which are curved. The first storey has these zones concave-convex-concave (coved-bowed-coved); in other words, this storey is serpentine in plan. The second storey has the zones all concave (coved); it is waved. The triple vertical zonation is obviously symbolic of the Trinity, but the central zone being convex below and concave above seems to be symbolizing the incarnation of the Son of God as one of the Trinity. Above, in heaven, he is equal to the other two persons of the Trinity (Father and Holy Spirit) but below, on earth, he is the only person to be directly accessible as an incarnate human being, Jesus Christ, and hence the central zone of the first storey advances to meet the viewer.

First storey[]

The first storey has four large Ionic columns supporting a serpentine entablature with a simple dedicatory inscription on the frieze: In honorem [Sancti]ss[imae] Trinitatis et D[ivi] Caroli MDCLXVII. The projecting cornice of this entablature is richly decorated with curlicued brackets interspersed with wreaths.

The columns are on a high plinth, and their capitals are wrapped in foliage, obscuring the volutes -an unusual touch. Six smaller derivative Composite semi-columns (note that the volutes are incurved, with swags) support three curved entablature fragments which divide the storey into six equal areas. The lower central one of these is the only entrance doorway, approached by steps because of the crypt. The two on either side have a device of a large vertical oval window, recalling the dome plan, enclosed in a pair of palm fronds clasped by a crown above. Below is a goat's head a device with the Trinitarian cross and a large drooping swag.

The upper central area, above the doorway, has a statue of St Charles Borromeo which is the work of Ercole Antonio Raggi. The statue is flanked by a pair of angel caryatids, who hold up two wings to form a false pediment. To either side are statues of St John of Matha and St Felix of Valois, the founders of the Trinitarian Order, which were executed by Sillano Sillani in 1682 and were the last additions to the church fabric. The statues are in apsidal niches enclosed in molded rectangular frames; St Felix is on the left, and St John is on the right. The latter is holding a model of the church of San Tommaso in Formis on the Celio, which belonged to the first Trinitarian convent in Rome and where he died.

Second storey[]

The second storey also has four large columns, but the capitals are different and can be described as derivative Composite. Each pair of columns supports a concave entablature with rosettes on the projecting cornice, and in between these is a very large oval tondo supported by a pair of angels and topped by a pair of curlicues forming a false pediment. The tondo used to contain a fresco of The Holy Trinity Crowning Our Lady by Pietro Giarguzzi of 1677, but unfortunately when the church fell into disrepair in the mid 20th century the damp in the fabric destroyed it.

As with the first storey, three pairs of smaller derivative Composite columns supporting cornice fragments divide the storey into six areas. In the lower middle area is an architectural device like a little oval mausoleum with an ogee cupola topped by a ball finial, and into this is inserted a large vertical rectangular window. The upper middle area is occupied by the flying angels supporting the tondo. The upper right and left areas have the Trinitarian cross again, this time in a tondo with a molded dentillate surround enclosed in a palm-leaf wreath and all within a molded rectangular frame. The lower right and left hand areas have empty statue niches; that statues were intended here can be seen from the vacant plinths intended for them.

The four main columns also stand on box plinths, connected by attics. The inner pair of plinths is connected by a bowed (convex) balustrade running in front of the central window. Although it is difficult to see from the street, the balusters in this balustrade are alternately normal and inverted. This design feature is more prominent in the cloister, and also features in the balustrade along the façade roofline which is mostly invisible from below.



The church integrates with the ground floor of the convent, as mentioned, and it is convenient to describe the overall layout.

On entering the church, you will find yourself in a space which is, overall, an incurved rhombus with rounded corners. Straight ahead is the apse of the main altar, and on either side is a subsidiary altar in a shallow segmental apse. The entrance occupies a fourth apse which is identical in plan to that containing the main altar. The altar on the right is dedicated to St Michael de Sanctis, and that on the left to St John Baptist of the Conception. Both of these were Trinitarian reformers, and the dedications of the altars were changed from the original ones when they were canonized.

Near the entrance is a pair of identical doorways; the one on the left leads to the crypt stairs and is not used, but the one on the right leads to a tiny chapel in the shape of an irregular hexagon. It is dedicated to the Crucifixion.

Flanking the apse of the main altar is another  pair of identical doorways. The right hand one leads into the convent, but the left hand one leads into another external chapel, larger than the one just mentioned and in the form of a squashed irregular hexagon. It is dedicated to the Holy Family, and is known as the Cappella Barberini. A beatified Trinitarian tertiary called Elizabeth Canori Mora is now enshrined here.

The door into the convent leads into an irregular little antechamber, and on the right at the far side of this is the entrance into the cloister. On the left side a corridor runs behind the apse, then turns left behind the Cappella Barberini to end in a fairly small rectangular room which is the old sacristy. A door at the other end of this leads to a spiral staircase which gives access to the crypt.

The present sacristy, which used to be the refectory, is on the other side of the far wall of the corridor behind the apse. It is accessed via a door in the south side of the cloister.

Church fabric[]

The dominant colour of the interior is white, hued with a hint of pink.

The main altar apse, the two side apses and the entrance apse all have slightly ogee curves. Each apse has four monumental derivative Corinthian columns, one pair framing it and one pair within, giving a total of sixteen. The capitals have little rosettes in place of volutes.

The columns support an entablature which runs round the entire church, and the ogee apse curves inform this to give the incurved rhombus with rounded corners as its shape. The cornice of the entablature is projecting, with rosettes, and the frieze is blank.

In between the inner and outer pairs of columns in each apse is a pair of empty trefoil-headed niches, with scalloping in the conchs. These contrast with four similar but slightly larger niches above the four doorways in between the apses, which have round-headed conchs and rayed scalloped decoration embellished with curlicues. It is obvious that statues were intended for the niches over the doors, as plinths are provided. 

The floor was re-laid in 1898, as the attractive central device in opus sectile indicates. This has the Trinitarian cross within an oval shield reflecting the dome plan, surrounded by a manacle and chain together with an epigraph: Munificentia piisimae Dominae Casildae Iturrizar, viduae Epalza Flaviobrigensis in Hispania, pavimentum hoc stratum adornatumque est AD MDCCCCXCVIII. The money came from a widowed Basque lady.

Over the entrance door is a large circular tondo which used to contain a fresco of the Annunciation by Pierre Mignard, who also painted the main altarpiece. This was destroyed by the installation of an organ in 1855; this has now been removed.


The interior dome is the church's glory. To achieve its position, Borromini raised three semi-domes over the three altar apses and embellished them with coffering containing rosettes. Over the entrance he placed a wide arch instead, with a single line of coffering on its intrados, and this arrangement allows light in from the large window in the façade (the only direct natural light into the body of the church). In between the arches he inserted truncated pendentives, and on these placed an oval cornice.

The pendentives have tondi with stucco reliefs by Giuseppe and Giulio Bernasconi, illustrating scenes from the foundation of the Trinitarian order. They are: The Meeting of SS Felix and John, Pope Innocent III Approves the Order, The Founders Receive the Habit and The First Ransoming of Captives.

On the projecting cornice of the dome are acanthus leaf finials, alternatively large and small, and below each large one is the Trinitarian cross again. The dome itself has a complicated and famous pattern of coffering, formed from crosses, octagons and squashed hexagons, and the coffering shrinks in scale until it meets the large oval oculus. Around the latter is a dedicatory inscription similar to that on the façade: Sanctiss[imae] Trinitati Beatoq[ue] Carolo Borromeo D[ivo] An[no] Sal[vatoris] MDCXI. The oculus contains a Trinitarian symbol, being the Dove of the Holy Spirit within a triangle surrounded by an octagonal glory, all in gold.

The pattern of the coffering was not Borromini's invention, but he borrowed it from an ancient mosaic at Santa Costanza. In turn, it is very likely that the design inspired the famous Dutch artist M. C. Escher , who lived in Rome as a young man.

Main altar[]

The main altar is placed against the far wall, and has an arched aedicule which fills the entire apse between the inner pair of columns. This aedicule is in gilded stucco with heads of putti, and the frame of the altarpiece has a trefoil top recalling some of the side niches mentioned. There is some detailing in verde antico marble, including on the large tabernacle which is the form of a shrine with a cut-away ogee cupola. The altar frontal is in alabaster with a device featuring the Trinitarian cross yet again. The same symbol is at the top of the aedicule, embellished with a little starburst glory.

The altarpiece, by a French artist named Pierre Mignard, shows SS Charles Borromeo, John of Matha and Felix of Valois Venerating the Holy Trinity.

Flanking the altar within the apse are two doorways with niches above them of the trefoil design. The niches once held statues of St John of Matha and St Felix of Valois.

Chapel of the Crucifixion[]

The little Chapel of the Crucifixion is to the right of the entrance. This was provided in 1653 with three paintings by a rather obscure artist called Giuseppe Milanese. There is a Crucifixion over the altar, a Scourging on the left and a Crowning with Thorns on the right.

Side altars[]

The two side altars are in gilded stucco, of almost identical design. The altars themselves are in what looks like Sicilian jasper, red and white, with some verde antico. The left hand one has an altarpiece showing The Ecstasy of St John Baptist of the Conception by Prospero Mallerini of 1819; it shows the saint levitating while adoring a crucifix. The altarpiece of the right hand one shows The Vision of St Michael de Sanctis by Amalia de Angelis of 1847. This seems to be the only work on view in Rome of this female artist from Florence, who (rather alarmingly) shows the saint and Christ swapping hearts. The little whip next to the skull is a discipline, used by religious of the period as a means of penance.

These two pictures replaced works by Giovanni Domenico Cerrini, depicting St Ursula and The Holy Family with SS Agnes and Catherine. These have been transferred to a corridor leading to the cloister, and you can easily spot where they originally were by the ogee curves to their tops. They are very much superior artistically to the rather academic paintings that replaced them.

Cappella Barberini[]

The external chapel on the left side is the Cappella Barberini, after the cardinal who promised to pay for the convent and church -the one who only put up part of the total cost. Six Corinthian columns arranged in a squashed hexagon support the incurved hexagonal vault, where the Barberini coat of arms featuring the famous bees can be seen in the gilded oculus. The epigraph around it commemorates Francisco Cardinal Barberini, and boasts that he was a nephew of Pope Urban VIII.

The chapel is now dedicated to Blessed Elizabeth Canori Mora, whose relics are enshrined in a modern little sarcophagus under the altar. Pamphlets and prayer cards concerning her should be available, and there is also a portrait of her on display. She replaced an alleged Roman solider martyr whose corpse was on view (oddly, his name and legend have not been readily traceable).

The altarpiece in this chapel is by Giovanni Francesco Romanelli, and depicts the Flight to Egypt. The setting shown is very bucolic, not at all like the Sinai in reality. Interesting is the cherub presenting a cross of twigs and a crown of thorns to the distressed Christ-Child, as this symbolism recalls that on the famous icon of Our Lady of Perpetual Help at Sant'Alfonso de'Liguori all'Esquilino.

A window in this chapel contains an attractive roundel icon of the Madonna and Child being venerated by a monk and a nun who don't look Trinitarian (Dominicans?).


This is now open to the public, after restoration. To get to it, go through the door to the right of the main altar apse, turn left and left again, pass through the original sacristy and go down the spiral staircase. This staircase also leads up into the campanile. It has a very unusual helically spiral central column.

The crypt itself is on the same plan as the floorspace of the church above, being an incurved rhombus, and is entirely painted in white. There is an altar at the far end, under the main altar of the church, and this has an attractive pietra dura frontal. The altarpiece is a wall fresco of the 18th century showing the Crucifixion, but damp penetration has seriously damaged this.

The walls have large round-headed niches interspersed with rectangular niches or doorways. Above these is an entablature which runs round the entire crypt apart from above the altar, and above this in turn is a lunette placed above each niche or doorway. A simple oval vault with a very shallow curve springs from between these lunettes without any decoration whatever, giving the impression of some dead sea creature.

The floor is in red brick. A doorway to the left of the altar leads to a little side chapel or room which is the crypt of the Barberini chapel above, and it is this that is pointed out as Borromini's intended tomb. It contains nothing. The overall impression in the crypt is that money ran out before any intended decorative or devotional work could be started.


The cloister is accessed to the right of the corridor leading from the door to the right of the main altar. It is a charming and intimate two-storeyed space, and is on the plan of a chamfered rectangle with arcades on all four sides. There is an octagonal well in the garth, surrounded by a brick floor (no plants). 

The chamfers in the first storey are bowed or convex, and are each flanked by a pair of Doric columns supporting a trabeation. The short ends of the cloister each has an archway supported by one member of these pairs of columns, and these archways correspond to convent doorways. The north doorway leads through a passage to the street, while the south doorway leads to the sacristy. The long sides of the cloister have two arches separated by a trabeation supported by another pair of columns on each side, giving a total of twelve columns in the ground floor arcades.

The second storey arcades have columns in the same positions, but these support a continuous trabeated entablature open to the sky. The walkways here have balustrades, and the balusters are alternately correct and inverted in a design feature already glimpsed on the church façade.

Note that there are no doorways in the western wall, because it belongs to the neighbouring former convent of Santi Gioacchino ed Anna.


The old refectory, now the sacristy, is accessed via the cloister and has the same chamfered rectangular plan. There are beautiful stucco decorations, featuring six-winged seraphs at the corners. The vault springs from a continuous entablature, with rosettes and tulips on the frieze and stars on the architrave. The central panel of the vault has an hour-glass shape made up of four double curlicues, but has no fresco.

There is a tiny but exquisite porcelain holy water stoup, the design of which is attributed to Borromini. 

The altarpiece of the altar here belonged to the original temporary chapel built by the Trinitarians, and this shows St Charles Borromeo Adoring the Trinity. It is by Orazio Borgianni, and is of 1611. Other pictures kept here include St Francis Renouncing His Patrimony, St Agnes, St Michael de Sanctis in Glory and an engaging secular picture of two little girls which looks as if it is of the 17th century.

In a room next to the sacristy is kept a portrait of Borromini.

The sacristy may not be obviously accessible to visitors. If you have difficulty, you could ask the custodian who should be on duty in the church. However, please don't ring the convent doorbell for the purpose or accost any of the friars who may be passing.


The access arrangements have now been regularized. You should find the church open at the times given below. On the other hand, don't bother ringing the doorbell at the convent to be let in at other times (as you may be advised to do in older guidebooks, and in online sources relying on them). You will only get the same information verbally, and with abruptness, if anyone answers the door at all. The brethren have better things to do.

Monday to Saturday: 10:00 to 13:00; the afternoon opening has been abolished. The church is only open for Mass on Sundays, and only those wishing to attend it are allowed in.


A public Mass is celebrated on Sunday at 11:00. Taking photos during the Mass will cause offence.

Special feast-days celebrated with solemnity are: Holy Trinity (first Sunday after Pentecost), St Charles Borromeo on 4 November, Blessed Elizabeth Canori Mora on 4 February and St John Baptist of the Conception on 14 February.

External links[]

Aerial view[]

  • Google Maps aerial view. The lower (south) corner of the central crossroads has the small dome of the church. The opposing (north) corner used to the edge of the grounds of the Palazzo Barberini, but the street frontage was sequestered for development in the 19th century. On the top (north-west) side of the Via del Quirinale leading south-west is the Quirinal Palace with its gardens. Adjacent to the convent of San Carlo is that of Santi Giacchino ed Anna, and you can just see the lantern of the dome of its deconsecrated church peeping out. Further south-west along is a grove which is the surviving remnant of the gardens of the Jesuit noviciate, and on the other side of this one comes to the dome of Sant'Andrea al Quirinale by Bernini which was its church. The long, low tiled roof to the south of the grove is the basilical church of San Vitale.