Taking a Look at Constantine's Basilica in the Vatican

Today is the feast of the Chair of Saint Peter--a feast that celebrates the apostle's ministry at Rome and it is a fortunate coincidence that we are looking at the basilica that Constantine built over the tomb of the Apostle two and a half centuries after Peter's martyrdom.  Constantine’s Basilica no longer stands. It was demolished over the course of the sixteenth century to make way for the current St Peter's Basilica.  There are few representations of the original church—one of the more notable is in the Basilica of San Martino ai Monte in Rome.  This fresco was painted sometime probably in the 14^th century when the basilica was approximately a thousand years old and had been considerably altered from Constantine’s day.  Notice the tabernacle (the canopy) over the altar with its tall pointed super-structure. While such tabernacles were all but universal in Roman churches, I haven’t come across the description of this one, but it roughly corresponds--not in detail but in general idea--to the still standing tabernacle of the basilica of Saint John Lateran by Arnolfo di Cambio .  We know this is a fresco of the Vatican Basilica because of the pigna (the large bronze pinecone) which stood in the center of the open courtyard in front of the medieval basilica.  It now stands in a courtyard of the part of hte Vatican palace used as the museum. 

While the original basilica no longer stands, we can have an idea of what it looked like by looking at features of several other churches that in various particulars resembled Constantine’s shrine over the tomb of the apostle.   

This next  picture is of the Basilica of Saint Paul fuori le mura (outside the walls) the Constantinian Basilica constructed over the tomb of the Apostle Paul.  Unfortuantley a fire early in the nineteenth century all but destroyed the ancient basilica and this is a 19^th century building but built on Constantine’s original plan.  Like Constantine’s Saint Peter’s it is a five aisled basilica with a transverse on the far end from the middle of which extends an apse.  while slightly larger than Old St. Peter's, the proportions are roughly the same.   We see here only the central aisle, the two aisles that flank it on either side are barely visible but the immense width not only makes the flanking aisles a necessity to support the roof, it also gives a spacious feel to the entire nave.

At  the far end of the nave, just before the transverse crossing at the far end, stood a "triumphal arch" on the idea of the arches the emperors had built to mark their victories.   The triumphal arch separating the nave from the apse of the basilica of Santa Praessede in Rome, pictured to the right,  is somewhat typical of such an arch that stood at the head of the aula or nave of the Constantinian Basilica of Saint Peter, separating it from the transverse and the apse beyond.   In the center one can see the Paschal Lamb on the Book of Seven Seals mentioned in the Book of Revelation.  On either side stand the winged figures representing the four evangelists.  Beyond them haloed figures of the apostles and beneath the evangelists and apostles one sees the elders of the Book of Revelation with their golden crowns.   

The ancient basilica of Santa Maria in Trastevere also has a triumphal arch—in fact it has two of them.  The forward one has mosaics of the renaissance period, but the one in front of the apse has a central roundel with a cross and the alpha and omega representing Christ.  On either side of the roundel one can see angels and below them the prophets.  The arch at St. Paul outside the walls which can be seen in the picture of that church illustrating the five aisled nave has a central roundel with Christ in his humanity and the evangelists, two on either side of him.  beneath them are a host of saints in adoration.  Because of the consistency of theme, we can presume that the arch in St. Peter’s was decorated with a depiction of Christ in the center and probably with the evangelists and apostles somewhere in the design.  Of course, remember that in history the word "presume" is a very weak word; while the central figure being Christ is all but certain, we do not know the remainder of the design with any certainty.   

In almost all of the ancient and early medieval churches of Rome the altar is crowned with a tabernacle.  American Catholics think of the tabernacle as being the repository for the Eucharist left over from mass and reserved for the communion of the sick and dying, but classically the tabernacle is the stone canopy over the altar.  Technically a tabernacle is a tented structure.  Before the Council of Trent these stone canopies were hung with draperies that could be closed to conceal the altar—and indeed conceal the mass itself—and this was traditionally done in penitential seasons.  In times of interdict or mourning the altars were ordered to be “veiled” which meant the drapes were to be closed.  In most of the Eastern Rites there was either an icon screen or a curtain hung between the area around the altar and the congregation.  If it is a curtain it is closed for certain portions of the liturgy and/or during certain seasons of the year—again usually penitential times.  If there is a screen as in the Byzantine and several other rites, then the doors in the screen are left open on major feasts and closed at other times—and with a drape behind the doors at the most solemn times.  These drapes suspended from the tabernacle performed the same function.  The liturgical reforms of the sixteenth century Council of Trent did away with them.  Above we have pictures of the tabernacles of two old churches—on the left San Giorgio in Velabro  (7^th century) and on the right Santa Maria in Trastevere (4^th century).  Old Saint Peter’s also had a tabernacle, though we don’t quite know its design.  In the drawing below it appears as a rather boxy affair with arches beneath the arched canopy rising from the four columns and beneath the round chandelier suspended from the architraves.  Personally I doubt it was this boxed as most tabernacles that survive are more open affairs.  The next episode will be the changes that Gregory the Great made in the Basilica.