Few places better exemplify the nature of Rome as a city of layers than the beautiful Basilica di San Clemente. Under the 12th century basilica is a 4th century church, beneath which are the remains of a building that dates back to the 1st century. And at an even lower level there is a fourth stratum of buildings that were destroyed in the great fire of 64 CE, during the time of the emperor Nero (r. 54-68).
To make sense of all the layers, it is important to understand that the level of the valley in which San Clemente lies was about sixty feet lower in the first century than it is today.
San Clemente was built during the reign of Pope Paschal II (r. 1099-1118), but for centuries it was thought to date back to the 4th century. The existence of another church, at a lower level, went completely unsuspected until 1857 when a Dominican priest and amateur archaeologist, Father Joseph Mullooly O.P., made the discovery of his life.
Father Mullooly and his team dug through more than 20 feet of rubble to reach an earlier church, sitting almost directly beneath the present one. This was not an end to his discoveries, for below the newly excavated church, he later came across part of an insula (an ancient Roman apartment block) from the Republican era. Subsequent excavations by other archaeologists revealed a house and a mithraeum, both from the Imperial era.
San Clemente is one of the few medieval churches in Rome to have retained its atrium or courtyard, which is entered through a 12th century portal, known as a prothyrum.
On entering the church one’s eye is drawn immediately to the stunning mosaics
in the apse, some of the most beautiful to be seen anywhere in Rome.
The nave is lined with a motley collection of ancient granite and marble columns. The pavement is laid out in a style known as Cosmatesque, after the Cosmati
family, workers of marble, who flourished during the 12th and 13th centuries. The style, also known as opus alexandrinum, was used most extensively for church floors, but also for pulpits, columns and Episcopal thrones. The Cosmati used marble salvaged from the ruins of ancient Roman buildings, which they sliced and diced to create their geometric designs.
Discs of porphyry and granite lead to the schola cantorum, the 6th century choir enclosure, which was rescued from the older church. It is decorated with the monogram of Pope John II (r. 533-55). The ambo on the left side and the Paschal candlestick were later additions.
A marble screen separates the main body of the church from the high altar, where we find the tombs of St Clement, to whom the church is dedicated, and St Ignatius of Antioch. There is an image of an anchor (the attribute of St Clement), entwined with a cross, on the canopy over the altar. At the back of the apse is an ancient throne.
The Castiglioni Chapel, which sits at the beginning of the left aisle, was the first chapel in Rome to be frescoed following the election, in 1417, of Oddone Colonna as Pope Martin V (r. 1417-31), an election which brought to an end almost fifty years of schism, when the Church had more than one pope.
San Clemente was remodelled during the reign of Pope Clement XI (r. 1700-21), whose coat of arms we see throughout the nave. The ionic capitals on the ancient columns were refashioned to make them look uniform, elaborate wooden ceilings were inserted and paintings were added to the upper part of the nave. They depict scenes from the lives of St Clement (south wall) and St Ignatius of Antioch.
The original 4th century basilica, and the ancient Roman remains, can all be visited. The earlier basilica was slightly larger than the later one, which basically replicated its design. A few frescoes from as early as the 9th century have survived.
Underneath the 4th century basilica are the remains of two buildings, which are separated from each other by a narrow passageway. On one side of the passage is a brick insula (an ancient Roman apartment block), while on the other side are the ground-floor rooms of a mansion from the 1st century CE. The latter may have belonged to Titus Flavius Clemens, who is thought to have been executed in 95. His house might have been the venue for gatherings of Christians until the church was built in the 4th century. Clemens is not to be confused with his contemporary, Pope Clement I (r. c. 91 - c. 101), to whom the church is dedicated.
Across the passageway are the remains of a small Mithraic temple (late 2nd or early 3rd century). It consists of an ante-chamber with stone seating, a triclinium (dining-room) with a marble altar and a third chamber, which may have functioned as a room for the instruction of neophytes. The seven niches in the chamber might represent the seven stages of the initiation into Mithraism.
Mithraism was a mystery religion, which was practised across the Roman Empire from the 1st to the 4th century CE. Membership was restricted to men and the religion was particularly popular with Roman soldiers.
My name is David Lown and I am an art historian from Cambridge, England. Since 2001 I have lived in Italy, where I run private and
small-group walking tours
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