The Archbasilica of The Most Holy Saviour and of Saints John the Baptist and the Evangelist, commonly known as St John Lateran, is situated in the area of the Caelian Hill.
Originally, before the construction of the basilica, the ancient family of the Laterani owned the area, and lived nearby. The Annales of Tacitus in the year 65 AD record a confiscation of the land by the Emperor Nero, due to the involvement of some members of the family in a plot against him.
The land subsequently passed into the possession of a certain Fausta, the wife of Flavius Valerius Constantinus, who after the death of his father in 306 was proclaimed emperor.
Emperor Constantine – through the Edict of Milan - gave freedom of worship to the Christian community in 313. So as to give the nascent Church a suitable place for celebrating its feasts, he gave to Pope Melchiades the lands of the Lateran estate, that had come to him as part of his wife’s dowry, in order that the Pope might build a church there.
The Basilica, consecrated in 324 by Pope Sylvester I, was dedicated to The Most Holy Saviour. In the 9th century Pope Sergius III also dedicated it to Saint John the Baptist and in the 12th century Pope Lucius II added Saint John the Evangelist to the title.
From the 4th to the 14th century, when the pope moved to Avignon, the Lateran was the main seat of the papacy, thus becoming the symbol and the heart of the Church’s life.
In 1378, with the election of Gregory XI, the see of the pontiff returned to Rome, but the Pope decided to move the seat of power to the Vatican, since the Lateran was in very poor condition.
In 1650, Pope Innocent X commissioned a wholesale reconstruction the Basilica, entrusting the work to Francesco Borromini.