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Rome preserves some of the most important early Christian sites in the world – a virtual window into the life, times and profile of the first generations of Christians.  One of the most fascinating and accessible of these early Christian sites is the Basilica of San Clemente.  

Located just steps away from the Colosseum, the Basilica of San Clemente is a deceptively unremarkable place as viewed from the street.  To find San Clemente, walk to the far side of the Colosseum (away from the Forum) and follow a small street called S. Giovanni Laterano.

At the beginning of this street, one passes the excavated remains of the Ludus Magnus, a gladiator residence and training center that was accessible to the Colosseum via an underground tunnel.  Just a couple of blocks further up the street, on the left, there is a small green door entrance to the Basilica of San Clemente. The door is like a wormhole in time – a portal to centuries of Christian history – all the way back to the first generation of Christians.



There are a number of churches in Rome called “titular” churches. These ancient congregations trace their history back to privately held buildings – much as we would refer to a person who has the title of a house. As distinguished from buildings known by their public function or those that belonged to associations or foreign groups (such as synagogues), these titular buildings usually were referred to by the name of the person who owned the building and hosted the congregation. The Basilica of San Clemente is one of these titular churches.

The current street-level church was built in the 12th century when the former building, built in the 4th century, had become unstable due to earthquakes and the ravages of time.  During the late 1800’s, an Irish Dominican who lived and worked at the church, wanted to verify legends about its history and began digging under the 12th century building with a pick. He soon discovered not only the 4th century church but also 1st and 2nd century Roman buildings under it. Now, thanks to decades of excavation and research, we can visit all the levels of this site.

The church is located in a valley between the Esquiline and Caelian hills (two of the original seven hills of Rome).  This had been a densely populated area of Rome until Nero’s fire in 64 destroyed most of the buildings. Nero built his great Golden Palace (the Domus Aurea) above this site and dug a large lake and established vast stretches of unoccupied land nearby to create the appearance of a country villa in the midst of the most densely populated city in the world! 

After Nero’s death, the Flavian family sought to obliterate vestiges of Nero. They filled in the lake and built the Colosseum, built baths over the foundations of the Domus Aurea, and began to use this vast swath of unoccupied land to build other structures.

It is believed that the buildings under the 4th century church were constructed in the 1st and 2nd centuries under the auspices of the Flavian dynasty.  One appears to be a warehouse and, as we will discuss later, was probably a place where some of the earliest Christians in Rome met.

Due to the silting of the area below these two hills, the ground level around the 1st and 2nd century buildings rose so that the 4th century church built on them was then at street level. Over the next 800 years, the ground level continued to rise so that when the congregation built the 12th century church over the 4th century one, it too was at street level.  Thus, our portal in time requires that we descend 11 meters below the current street level to explore this history of one of the earliest Roman congregations.  Below is a set of drawings that gives some idea of the site.

12th Century Level

The 12th century church is a modest size building, erected in the style of a classical basilica building.  Basilica was the name given for a Roman building used primarily for legal affairs and transactions. The Romans had developed a way to create large interior spaces by laying a wooden beam pitched roof over parallel rows of columns.  Larger basilicas included several side isles of decreasing height so that windows could be created above them to let in light.

In Roman basilicas, a circular niche (apse) was created for the official’s seat.  When Christianity had grown in size and political clout – notably during the reign of Constantine, they adapted the basilica style building to create larger spaces for gatherings and worship. The apse was used as a focal point of the building where the person presiding at the liturgy would sit.  This architectural develop-ment changed the dynamics of Christian gatherings. Home-centered gatherings probably involved seating around a table or in a small gathering space so that congregants and leader were closer to one another and involved less spatial separation or distinction.  Long basilica style buildings created more spatial separation and a linear way of organizing a group so that the congregation began to take on more clearly defined hierarchical differentiation.

One is immediately drawn to the magnificently decorated apse inside San Clemente. This is arguably one of the most beautiful mosaics in all of Rome. It was created by Byzantine craftsmen in the 12th or 13th century. It continues a long tradition of using art to create both spiritual experiences and to convey religious truths to a largely illiterate population. The mosaic depicts the heavenly triumph of Jesus and the cross as the Tree of Life from which human beings derive their salvation and life.

For Christians visiting Rome, the mosaic in San Clemente (or at other churches), is a fun way to inventory Christian symbols and their meaning. A sample of the symbols in this mosaic alone include:


Lamb of God (center) = Jesus

Twelve lambs (bottom) = twelve tribes of Israel, twelve apostles

Lion/Bull/Eagle/Face of man (top)  = 4 Evangelists

Hand from heaven (center top) = God’s hand/providence

Tree of life = cross

Vine and the branches = Jesus and the Church

Four Rivers/Living Waters = Rivers of Paradise and Baptism and Jesus’ life/Spirit

Bethlehem = City of Jesus’ Birth

Jerusalem = City of Jesus’ Death and Resurrection

Palm trees = paradise/eternal life

Keys = authority (Peter)

Scroll = word of God (Paul)


The mosaic is dominated by extensive looping of vine branches rising out of the foot of the cross.  Two deer drink from the flowing waters, symbolic of the soul drinking from the living water that is Jesus.  The hand of God reaches down over the cross as a sign of the act of God in saving humankind.  The four evangelists hover over the apse. On the right side of the mosaic, sit Peter and Clement; on the left side Paul and Lawrence.  Peter is depicted with the keys of the kingdom (symbolic of the authority of Peter and the Bishop of Rome - Pope); Paul with a scroll (symbolic of his teaching and Biblical writings).  Lawrence sits on the grill over which he was burned/martyred for his faith; Clement sits next to Peter over a boat and fish, symbolic of his role as successor of Peter and his martyrdom where he was cast into the sea with an anchor tied to him.  The Prophets, Jeremiah and Isaiah, are symbolic of the prefiguring of Christ by Jewish prophets. 

Jesus is presented as the “Pantocrator” – no longer as sacrifice on the cross but as the one who comes to judge the living and the dead at the end of time.  A large blue banner reads:  “Glory to God in the highest and peace to men of good will.”  Just below that is the Chi Ro symbol of the cross with alpha and omega hanging from them – meaning Jesus is the beginning and the end (Greek letters at beginning and end of alphabet).  Four doctors of the Church sit below the cross – Ambrose, Gregory, Augustine and Jerome. 

For evangelical and reform Christians, the symbols that are Biblically based are easy to recognize and reinforce the continuity of Christian belief.  In 12th century Rome, Christians are drawing on early Biblical metaphors to express their faith. The prominence of Peter and Paul obviously express Roman Christians’ pride in being a Church where these great apostles witnessed to the faith and nurtured the first generation of Christians. But the inclusion of the “keys” in Peter’s hand is clearly part of the Roman perspective that authority resides in Peter and his successors.

The marble choir stall in the center of the church was taken from the earlier 4th century church (it was probably crafted in the 6th century).  It is a gorgeous architectural piece with intricate carvings and decoration. It is, however, a distinctively Roman Catholic element. For evangelical and reform Christians who criticized the clerical culture of Roman Catholicism, the idea of separating the priests or canons of a church from the ordinary faithful undermines the radical egalitarian roots of the Christian community.  As we will point out later, earliest Christians may have met in simple rooms around the courtyard of the warehouse to celebrate a shared meal and prayer. The differentiation between ordinary Christians and their leaders through the use of a choir enclosure, underscores how Roman Christianity changed over the centuries from the practices of its earliest generations.

Ironically, small gatherings of the faithful today sit in the choir enclosure with the priest who leads worship making services more like the earlier generations than like those in the medieval times. Indeed, the reform of Roman Catholic liturgy since the 1960s has sought to return to earlier forms where, for example, the presider faces the congregation who gather around the table and where the entire community (priest and faithful) make Christ present as they gather in his name.

(Top) View of apse mosaic.  (Below) View of 12th century basilica with mosaic apse and marble choir enclosure. 


Entrance to the Excavations and Lower Levels of the Site

The entrance to the lower levels of San Clemente is accessible through a room opposite the entrance.  A nominal entrance fee is charged for visiting the scavi (excavations).   There is a large staircase that descends to the 4th century level.  Fragments of sarcophagi and inscriptions line the wall.  When you arrive at the bottom of the stairs you are standing in the foyer just outside what would have been the main entrance to the 4th century church building. 

In the 4th century, Emperor Constantine erected a large basilica-style building over the tomb of Peter on the Vatican hill and one over the tomb of Paul on the Via Ostiense – both in 324.  The basilica over the tomb of Paul was enlarged at the end of the 300s when the older building could no longer accommodate the large crowds gathering there.  Earlier, Constantine donated property and buildings on the Laterani family estate to the bishop of Rome, Sylvester I, in 314. St. Peter’s, St. Paul’s and St. John Lateran were monumental buildings. Of the three, St. Paul’s gives us the best idea of what a late 4th century monumental basilica would have looked like since in 1823 it burned and was rebuilt according to the original plans.

Throughout the city of Rome and the Empire, after Constantine’s con-version, Christians began to erect local churches. They had ceased being a persecuted sect and could now openly celebrate their faith and confidently invest in the future. The 4th century church at San Clemente is perhaps the best example in Rome and in the world of a local church building (as opposed to more monumental imperial buildings).  As you walk in the front door of the church, you are walking into the proud edifice of a local Christian congregation. Imagine the excitement they must have felt when they gathered for the first time to celebrate the Lord’s Supper, to read from the Scriptures, and to sing hymns in their new building.

The center support for the upper level building and the foundation for the upper level apse make the lower church appear smaller than it really is. The actual side pillars of the 4th century basilica are to the right of the support wall. The apse of the lower church is behind the 12th century support apse (this is confusing unless you purchase one of the overlay maps in the bookstore upstairs).

The apse of the 4th century church was not built until later in the 4th century or probably even in the beginning of the 5th century. As we will discover on the level below, a Mithraic temple existed in the adjoining set of buildings. Until pagan cults were banned in Rome, there was an active congregation of Mithraic believers next door to the Christian church that prevented extending the back wall with an apse. Visiting this site provides a great opportunity to consider and discuss how Christianity would have compared with other religions, how Christians differed from their neighbors, and what made Christianity ultimately more appealing to Romans than Mithraism or traditional Roman religious beliefs.

To the far left of the nave there is a staircase that descends to the 1st and 2nd century level.

There is some dispute about the date of the buildings on the lowest level, but there is growing consensus that they post-date the Neronian fire in 64 (there are some charred remains under them) and post-date Nero’s reign since during Nero’s time, this area was devoted to the Golden Palace and its surrounding gardens.

When Vespasian built the Colosseum in 72, a number of buildings were erected in this area – including the Ludus Magnus (gladiator training center) and other structures needed to store equipment and supplies for spectacles held in the arena.  Under San Clemente, archaeologists discovered a large warehouse with storage rooms facing an interior courtyard and a residential building that included rooms that were converted into a Mithraic temple.

The cult of Mithras, a Persian and Indian god, spread West through the Greek Empire of Alexander the Great and became popular among Roman soldiers from the late 1st century BC until it was suppressed in the 5th century.  

Mithraism was a mystery cult or religion. Mystery religions were voluntary associations that involved a secret initiation into membership in the cult as a means to achieving salvation.

In Mithraism, members were “reborn” through a ritual bath, were received into the community with a ritual handshake, and were then part of the community who shared in a sacred meal of bread and wine consecrated by “fathers” in intimate cave-like rooms where the story of Mithras was retold and reenacted. Mithras was born from a rock, miraculously produced water, wrestled a wild bull back into the cave and slayed it. The bull was sacrificed so that new life could be produced. There were mythological connections between the bull and the moon and Mithras and the sun – so that the story of Mithras involves a cosmic struggle and sacrifice, not merely an earthly one. The Christian writer Tertullian believed that the similarities between Christianity and Mithraism were so close that the devil must have invented Mithraism to dupe people away from the true faith. 

The Mithraic temple under San Clemente is very well preserved with an altar, side benches for reclining at meal, and astrological decorations in the ceiling. Across from the “cave” is a room probably used for instruction. The temple was created out of one of the rooms (perhaps a semi-subterranean grotto) of a 1st century residence. This residential building was separated from the warehouse by a narrow alley.

The warehouse might have been part of the Mint of ancient Rome or perhaps used in association with events at the Colosseum.  Either in its original state or later (after undergoing some modifications), the building was probably a gathering place for Christians.

It is possible to walk through some of the storerooms. Artificial passages have been cut between the storerooms (these were not original). The outer walls of the warehouse were without windows. The interior courtyard has not been excavated. Thus, it is difficult to imagine the space or how it was used.

The name of the site tells us something of the sociological status of the earliest Christians. As in the house church at the home of Prisca and Aquila, Christians relied on those of some means to provide hospitality for their gatherings. Since this area of Rome was not a neighborhood of the poor, it is possible that those who gathered here were either people of means or those who worked for people of means.


Who was Clement?

An interesting question for Christian historians is that of the identity of “Clement.”  References to Clement include writings of St. Irenaeus (130-200) who considers him a contemporary of Peter and Paul.  Origin (185-254) believes he is the one that Paul refers to as a fellow worker in Philippians 4:3. Some scholars believe Clement was a Jewish ex-slave in the household of Titus Flavius Clemens, cousin of the Emperor Domitian (81-96).[i]  Since it is likely that the land on which this titular building was erected would have belonged to the Flavian household, there is good probability that whoever Clement is, he was part of the Imperial household. 

This could be the same person who wrote the Letter to the Corinthians in 96 AD to deal with the problem of some presbyters who had been deposed.  If so, he was one of the early bishops of Rome (or, according to Roman Catholic belief, the fourth “Pope”).  According to other legends (in the “Clementine Literature” and in the “Acta,”) Clement was sent to Crimea under Emperor Trajan (98-117) and thrown into the Black Sea with an anchor tied to him because he was so successful at converting soldiers and fellow prisoners to Christianity.  Later water receded and revealed a tomb that had been built around Clement’s body by angels.[ii]  These legends are depicted in some of the faded frescos in the 4th century level.


Educational Uses of a Visit

Visiting the Basilica of San Clemente offers many learning opportunities. 

Contrasting the small gathering spaces in the warehouse and the Mithraic temple with the 4th century and 12th century basilicas, one can explore how architecture shapes the sense of church, congregation and worship.  Christians moved from small egalitarian gatherings to those that were larger and more structured. The very style of a basilica building lends a certain solemnity to the service and to the person leading the service.

The location of the site underscores the privileged connection some early Christian leaders had in Rome (since the site is probably under the jurisdiction of the Imperial family).  While many Christians were poor and immigrants, the Basilica of San Clemente suggests there were also congregations made up of the more affluent and well-connected citizens of Rome. We can imagine tension arising between those who saw Christianity as a new religion that would overturn the established order and those who saw Christianity as a new religion that would transform traditional Roman religion and society (but not destroy it).  We see some of this concern for transformation rather than revolution in Clements’ letters addressing concerns in Corinth. A visit here provides a great opportunity to discuss different models of the relationship between Christianity and culture.

Since the earliest generation of Christians gathered near an active  Mithraic temple, the site offers opportunities for interfaith discussion.  What relationship did Christianity have with Roman religion? What challenges did couples or households face where they practiced different religions? How was Christianity like other “mystery” religions?  How was it different? What was the relationship between practitioners and/or leaders of other religions and Christianity? Apparently the Mithraic temple continued to operate even after the construction of the 4th century basilica (preventing the early construction of an apse).  Was the relationship between these two communities cordial or hostile? What can we learn from these earlier generations about our own time? 

For many groups, the Basilica of San Clemente offers a tangible way to affirm the continuity of Christianity – from the 1st century to the present.  There are few places where we are able to stand in a place where Christian worship has been taking place since the earliest generations.  A visit here emphasizes the responsibility each generation has for passing on the tradition, teaching it to the next generation, and witnessing to the first courageous believers who offered their lives for the Gospel – Peter, Paul, Lawrence and others.

The religious art here (frescos in the 4th century level and mosaics in the 12th century level) showcases the Biblical stories that were adopted by the earliest generations of Christians and continue to engage the imagination and faith of subsequent ones. Just as these stories evangelized the first converts, they continue to evangelize those who encounter them today.  Religious architecture and art are great mediums for telling the Christian story and providing images that address not just the mind but the heart as well. 

The Basilica of San Clemente can be reserved for religious services by various groups. Whether groups gather in the intimate space of the choir stall in the upper basilica or in one of the areas of the 4th century lower level, the idea that one gathers where countless others have gathered before creates a profound bond across generations.  One gains a sense of being part of something much larger than oneself – a part of a history that transcends the particular issues and concerns or our own time. Come explore the people, places and world of the first generations of Christians in Rome!


Practical Information

Location: The Basilica of San Clemente is located on the Via San Giovanni just three blocks from the Colosseum. 

Hours: As of the publication of this article, the church is open from 9 AM to 12:30 PM and then from 3 PM to 6 PM.  Excavations open same hours except Sundays and holidays 1215 PM - 6 PM. Entrance is 10 Euros. The excavations are closed on Christmas.


[i] A Short Guide to St. Clements, Leonard Boyle, OP., 1989, p. 4.

[ii] Ibid., p. 4.



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