Basilica Costantiniana
by Lex Bosman, appearing in Volume 46
Anyone entering the present church of San Giovanni in Laterano for the first time will probably not immediately be aware of the historical importance of this place, nor of the history hidden in this great building. For here a fascinating accumulation of historical periods is present, which is not well and certainly not immediately visible. The construction of this church most probably started in the winter of 312. In this article, we dwell on the genesis of San Giovanni in Laterano and the most important renovations in the centuries that followed.
From Castra nova to basilica
The site where San Giovanni in Laterano was built had been in use before and several buildings had stood there, whose remains have become known through archaeological research. Before construction of San Giovanni began, a large complex had to be demolished, namely the barracks of the imperial cavalry, the Castra nova equitum singularium. And before 193 A.D. when this camp was built under emperor Septimius Severus, some houses existed here of which remains have been found, including part of a house from the time of Nero.
In this area in the southeast of the city, close to the Caelius, there were villas and other buildings dating back to the Republican period. The buildings were further expanded in the Imperial period. The name of the area, and hence the name of the later basilica, dates back to this time, when Septimius Severus donated a rich residence to Titus Sextius Lateranus. Under this emperor towards the end of the second century, the imperial guard, the equites singulares, expanded and therefore a new army camp was needed, so the Castra nova was built. But about 120 years later this camp was razed to the ground. Indeed, on October 28, 312, Constantine defeated his opponent, Maxentius, and thus became lord and master of Rome. Constantine, meanwhile, was sympathetic to Christianity, but there is much debate as to from what moment and for what reason he took that stance. Constantine was only baptized relatively late, shortly before his death, and it seems likely that his was not a direct, obvious choice for Christianity and thus automatically against the Roman gods. For quite some time, on the contrary, he seemed to have had respect and awe for both sides, so he supported and promoted the Christian religion as well. Sometimes he interfered in Church affairs as a kind of head of the Church and at various building commissions there will certainly have been extensive consultations between Church dignitaries and Constantine and his closest advisers. For example, details are known from the Liber Pontificalis (its first edition dates from the first half of the sixth century) about Constantine’s involvement in the foundation of the so-called fastigium in San Giovanni in Laterano, which we will discuss in more detail later in this article.
The imperial cavalry was probably disbanded because these warriors had fought along-side Maxentius. The barracks thus became redundant and with it a spacious area of land became available which was further extended on the north side with land the emperor had confiscated from Nero’s former property. The barracks were demolished to make way for the church of the bishop of Rome: a clearly visible imperial-military presence was thus replaced by what might be called an imperial-religious building. The way in which all this happened has become more clear through recent research.
The barracks, consisting of a rather large building complex, was demolished, which probably also provided building material for the construction of the basilica.1 The old walls and foundations of the barracks buildings were not reused in the process, however—it is visible that the basilica was built at a 90 degree angle to the Castra. In the wall of the foundation on the north side of the nave, it is easy to see that the material here was treated and processed rather roughly, with recognizable fragments being incorporated into the foundation wall on closer inspection, such as fragments of fluted columns. (These are columns with vertical, hollowed-out grooves.)
This first large basilica for the Christians of the city of Rome was initially called Basilica Constantiniana, named after its main patron or donor, as was customary. Other basilicas were also named after the principal donor, such as the Basilica Aemilia. Also, although these basilicas were used for different purposes, in essence the use of the spaces did not differ substantially, as will become clear later in this contribution. The naming already points to Constantine’s great involvement in this project. Later on, the building was known as Basilica Salvatoris, still later as San Giovanni in Laterano, or Saint John Lateran.
The complex, besides the church, also included a baptistery, to which the basilica owes its patron saint. Excavations and new research have made some things clear about the building history of the baptistery, but far from everything. The octagonal building stands on a circular foundation and the structure may date from the third decade of the fourth century. The eight red-porphyry columns were assembled as spolia by Constantine for this building. (The term spolia refers to visibly reused material in buildings.)2 Until well into the fourth century, this was the only baptistery in Rome.
What came about with the construction of the Basilica Constantiniana is certainly worth noting: here was built a basilica with a wide central nave and four side aisles, an apse with altar space in front of it, but no transept. With a length of 99.76 meters (327.29 feet) from the inside of the façade to the deepest point of the apse, a large building was realized, intended and suitable to accommodate large groups of Christians and serve as a dignified church building for the bishop of Rome.3 Despite later modifications and alterations, this spatial layout based on the fourth-century ground plan has remained virtually unchanged.
The location of the basilica: a tactical choice?
On the reason why the Basilica Constantiniana was built far from the ancient and important center of Rome, there are essentially two views. In the first view, posited among others by architectural historian Richard Krautheimer, the choice of the site close to the Aurelian wall (built in the third century) would have been mainly determined by tactful action of Constan-tine towards the largely non-Christian aristocracy of Rome, which he would not want to offend. Therefore, an inconspicuous and barely populated site would have been chosen for the basilica for the Christians, thus leaving the ancient secular center of Rome untouched.
Another view, which in the last twenty years has gained quite a bit of ground, on the other hand, emphasizes that the area in the southeastern part of Rome was indeed inhabited and had had an imperial presence for much longer through extensive imperial possessions and associated buildings.4 In the previous section, we already saw that the area already had quite a few buildings before the Basilica Constantiniana was erected. The so-called Sessorium in the second and third centuries, where Santa Croce in Gerusalemme was later built, shows that Roman emperors had an ample presence here. Apart from a palace, it included a circus, an amphitheater, thermal baths, and gardens. Part of the outer wall of the amphitheater is still standing. That Constantine, primarily for considerations of tact would have chosen a site well away from the venerable and, for the tradition of Rome, important center therefore now seems less and less likely.
But the two views are not entirely mutually exclusive either. If Constantine had wanted to support the Christian community of Rome by enabling a large, and therefore notable church building in the center, it would have had to be made way for by demolishing something, and that would no doubt have met with great opposition and damaged Constantine’s credibility as emperor. Moreover, it was certainly also in Constantine’s interest to continue the tradition of Roman imperialism that was reflected in the buildings precisely in the center. This can be seen, for example, in the triumphal arch for Constantine that was erected in 315. But, on the other hand, it was of course true that this area in the southeastern part of the city of Rome had long been imperial property and a good deal of land became available due to the demolition of the barracks. In that way it all worked out and there was no need to upset anyone and the center of Rome remained intact.
The secularization of the Roman basilica
Especially in the past, much has been written and speculated about the “choice” of the building type of the basilica as the first major building for the Christians of Rome. Its use by Christians would then have transformed the Roman basilica into a “Christian basilica.”5
First, the question of whether the basilica building type was chosen. A choice presupposes alternatives, but actually there were none. For hundreds of years the basilica had been known as a structure in which many people could be gathered, but without a very specific function. Basilicas were used for justice, for markets, for political meetings, and therefore also as meeting places. Another important factor was that basilicas were mostly built to represent the show-power and prestige of the patron, for certainly emperors were expected to express their prestige and power in part through serious building commissions. Large building commissions, after all, could irrefutably and quite literally show who had the money and the resources to erect such buildings. That a basilica was thus built as a gathering place for the Christians of Rome is not so surprising: the basilica was, after all, the building par excellence in which large groups of people could be gathered.
There are several interesting theories about the use of basilicas by Christians, in which architectural historian Friedrich Wilhelm Deichmann distinguished three elements for clarity: the form, the meaning, and the use of the building. Jürgen Christern further thought along those lines and argued that terms like “Christian basilica” or “imperial basilica” were not concepts that referred to distinct building types in antiquity. He noted that these terms were retrospective notions and therefore proposed to speak of church-basilica, referring to the use of the building, while the designation of the building type basilica remains the same, thus maintaining consistency with the much larger group of basilicas.6
It is therefore important to explain the overall structure and layout of San Giovanni in Laterano, which is essentially no different from other basilicas. A wide central nave is flanked on either side by two aisles; on the west side there was the altar space. The nave was separated from the altar space by a so-called fastigium, a structure with four bronze columns on which rather large silver statues stood. At the front were statues of the Savior and the twelve apostles, at the back an enthroned Savior with four angels. This monument has long since ceased to exist, but the four bronze columns on which it rested are still present in the architecture of the sacrament altar, located on the south side of the current transept. The expensive material (bronze and silver) of this monument fitted well into the richly decorated interior of the church building, with a floor and walls lined with variegated marble and a gold-painted underside of the roof over the altar space. The Liber Pontificalis mentions the gold painting, and the discovery of the onset of an arch on which hooks are attached shows that at least up to a certain height, the walls were covered with slabs of marble.
No less important in this interior were the series of nineteen red-granite columns on either side of the nave and a total of forty-two much smaller green marble columns between the inner and outer side aisles. Of the red-granite columns, two remain, supporting the triumphal arch between the nave and the transept, while many of the green columns were reused in the seventeenth century in the niches with apostle statues. There was no transept originally.
Conversions of the Basilica Constantiniana
In the long history of San Giovanni in Laterano, there have been several renovations, sometimes out of necessity but also sometimes to adapt the building to changed views. For example in 896 there was an earthquake that caused major damage to the church building. In particular, the middle aisle then largely collapsed, after which in the first decade of the tenth century the rebuilding could be completed under Pope Sergius III. A transept was finally built at the end of the thirteenth century for which three pairs of red granite columns were removed to create a continuous trans-verse space. The 1349 earthquake also caused damage to the building. Two serious fires, in 1308 and 1361, created new problems; the latter fire destroyed the roof of the nave. The enormous damage that resulted from these disastrous events was repaired, and the restoration must surely have involved modifications to the building, which can no longer be traced or reconstructed in detail. For that, the reports of the damage give us too little detail. After the fire of August 1361, presumably as many as twenty-two columns in the nave were removed and replaced by masonry pillars, while some columns still remained partially visible. Other interventions removed even more columns. Also it cannot be ruled out that columns had already been replaced before the fourteenth century. But that the church building did not look the same around 1400 as it did in the early fourth century is clear.
In 1597-98 two columns of yellow marble—called giallo antico or nu-midian marble—from the portico on the east side of the church were used to support the organ platform in the north transept. What is remarkable about these columns is that they have exactly the same dimensions and workmanship as the eight columns of the same material originally used in the Arch of Constantine.
From 1646, San Giovanni in Laterano was extensively renovated by architect Francesco Borromini and several drawings were made for this work, leaving us today with an impression of the interior during the late Middle Ages. The large, wide pillars that separate the central nave from the inner aisles and the pillars that separate the inner and outer aisles are important and highly visible elements of this construction phase. In the pillars in the middle aisle are niches in which statues of the apostles were erected. Not easily visible is the fact that large parts of the rising walls were replaced or repaired during this period.
From the old Senate building of Rome, the Curia Iulia, the bronze doors were taken and placed on the east side of San Giovanni. The current façade was designed by architect Alessandro Galilei, who completed the work in 1735. With all these changes throughout its long history, the spatial layout of the fourth-century building has always been preserved, even after the major renovation under Borromini in the seventeenth century.
Competition with Saint Peter’s
In all this, we should not forget that for a long time the struggle for power in Rome determined who was elected pope, with San Giovanni in Laterano regularly being made the plaything of a power struggle between different families and with increasing rivalry with the Vatican church which held the sepulcher of the apostle Peter.7 In the fourth century, this did not yet play a major role, but when pilgrimage to tombs of saints in Roman churches, especially Saint Peter’s, increased during the Middle Ages, the lack of a saint’s tomb and relics made itself painfully felt in San Giovanni. During the Middle Ages, it happened that at the same time both in the Vatican and the Lateran, a prelate claimed the pontificate. The fact that the apostle Peter was buried in the church named after him, which the Lateran Basilica could do little to counter, played a role. In that context, it is interesting that Pope Sergius II (844-47) had a confessio built in San Giovanni in Laterano, which housed relics. The entrance to the confessio is visible in front of the main altar. This was a clear attempt to give the church building a disposition as had become common at the time in Roman churches, in which important relics of saints were kept. Incidentally it is not known what relics were then housed in the confessio.8
In short, at its foundation and construction in the first quarter of the fourth century, the Basilica Constantiniana was the church for the bishop of Rome and the Christian community and, as such, the most important church of Rome. The importance of that position changed during the Middle Ages, and due to the competition with the Vatican and the tomb of the Apostle Peter, the Lateran basilica lost its initial position as the most important church of Christianity to Saint Peter’s.