The Archbasilica of the Most Holy Savior and of Saints John the Baptist and the Evangelist, commonly called San Giovanni in Laterano, stands in the vicinity of Mount Celio. It is the mater et caput of all the churches of Rome and the world.
In this area, there was once a residence owned by the noble family of the Laterans. Their house stood near the Basilica, probably towards the current Via Amba Aradam, and the land covered the entire area that also includes the current basilica area. According to the “Annals” of Tacitus in 65 these houses and land were confiscated by the Emperor Nero, because Plautius Lateranus, consul
designated for the year 65, conspired against the emperor himself in the conspiracy known as the
“Pisoni”. After the conspiracy failed, Plautius was sentenced to death and expropriated of his properties, which passed to the Imperial Treasury.
Subsequently (around 201) part of this land was used by Septimius Severus, who in order to consolidate the number of his bodyguard formed by the equites singulares (selected knights) who had a barracks near the current Via Tasso, found himself in the need to build a second barracks to
accommodate the new recruits. For this purpose he chose the Lateran area, where the imperial treasury had various properties, first of all that of the Laterans, acquired with the Neronian confiscation.
In a part of these Lateran lands the emperor built a large military complex called Castra nova equitum singularium (New Barracks of the selected guards). The excavations, carried out on several occasions under the floor of the basilica and under the cloister, have brought to light various sections of the Severian foundations, and part of the elevation of the ground floor of the Barracks.
In the same period Septimius Severus donated another part of the confiscated lands to Titus Sextius Lateranus, a friend of Septimius Severus and his valiant commander in the Mesopotamian expedition. It is not known whether the emperor donated the same house that belonged to Plautius
Lateranus or Titus Sextius or built a new one, but it would have been, in any case, a dwelling so
luxurious and important as to constitute a topographical reference point and, even after their disappearance, in the Middle Ages the buildings that stood in the area continued to be indicated with the phrase iuxta Lateranis (near the Lateran), until arriving at the current name of the Lateran.
It must be said that it has been thought of a kinship relationship between Plautius Lateranus who died under the emperor Nero and Titus Sextius Lateranus, a friend of Septimius Severus. A distant
kinship between the two characters cannot be completely ruled out, it is also true that a precise
relationship between these two people and their homes cannot be demonstrated.
Subsequently these lands became the property, it is not known whether by purchase or by inheritance, of a certain Fausta, as a domus Faustae in the Lateran territory is mentioned later. It has been tried to identify the Fausta in question with the second wife of the emperor Flavius Valerius Constantine (280-337), to whose name the memory of the foundation of the Basilica is linked.
Raised at the court of Diocletian, Constantine was called to Britain by his father, the emperor Constantius Chlorus, and upon his death he was acclaimed Augustus by the army (306), a fact that, breaking the rules of the tetrarchic system, unleashed a violent struggle in which six pretenders (Maximian, Maxentius, Licinius, Galerius, Maximinus and Constantine) competed for the imperial title. After Maximian was eliminated (310), Galerius died (311), Constantine on October 28 312 defeated Maxentius at Saxa Rubra on the Via Flaminia (the Battle of Ponte Milvio), aided by that divine symbol that had appeared to him the night before the victory in a dream: an angel with a cross and the words IN HOC SIGNO VINCES, which Constantine promptly had painted on the shields of his soldiers.
After defeating Maxentius, Constantine goes to Milan and strengthens the alliance with Licinius, who, after Maximinus’ death, remains master of the eastern provinces (subsequently Constantine
also gets rid of Licinius, thus remaining sole Emperor). In Milan Constantine he also proclaims an edict (313) in which he recognizes Christianity’s freedom of worship.
Back in Rome, Constantine takes care to offer the nascent church a suitable place to fully carry out its spiritual ministry. At that time (4th century) in the Lateran area there were the domus Faustae, the house of Fausta, who, as already said, was perhaps that Fausta wife of Constantine and sister of Maxentius, that Fausta herself had brought as a dowry to Constantine, and the Castra Nova Equites singularium.
Constantine dissolves the body of the equites singulares, who had supported Maxentius and donates to Pope Melchiades the land to build a domus ecclesia. The Basilica was consecrated in 324 (or 318) by Pope Sylvester I, and dedicated to the Most Holy Savior. In the 9th century, Sergius III also dedicated it to Saint John the Baptist, while in the 12th century Lucius II also added Saint John the Evangelist.
From the 4th century until the end of the Avignon period (14th century), in which the papacy moved
to Avignon, the Lateran was the only seat of the papacy. The Patriarchate, or Lateran residence (the ancient Papal seat), annexed to the Basilica was the residence of the Popes throughout the Middle Ages. The Lateran, therefore, was from this period until the 14th century the seat and symbol of the papacy and therefore, the heart of the life of the Church. Five ecumenical councils were also hosted
there.
The Primitive Constantinian Basilica was very similar in plan to the current one, also with five naves, and the perimeter walls coincide more or less with the current ones. A rectangular hall divided internally into five naves by marble colonnades with Corinthian capitals; 15 columns with high
entablature on each side of the main nave and 21 columns supporting arches between the side naves. At the end of the central nave, to the west, there was a large apse. In the early Middle Ages the Cathedral was a precious treasure box of works of art. Already the emperor Constantine,
after having wanted the great Basilica, enriched it with a wonderful ciborium for the main altar.
