Yesterday was the Feast of the Dedication of the Archbasilica of the Lateran, or, to give it its full title, as cited by Wikipedia, the Major Papal, Patriarchal and Roman Archbasilica Cathedral of the Most Holy Saviour and Saints Johnthe Baptist and the Evangelist in Lateran, Mother and Head of All Churches in Rome and in the World.
From the time of its gift by the Emperor Constantine to the Church until the death of Pope Benedict XI in 1304 it was the usual residence of the Pope and the seat of his administration. Due to its dilapidation it was not used as the principle residence of the Popes when they returned to Rome in 1376, and definitively in 1420, although it continued to be the cathedral of the See of Rome, with a rebuilt palace alongside and since 1929 has been an extraterritorial propert of the Holy See.
The Lateran at the beginning of the fourteenth century
A reconstruction from 1905. The view is from the north as, like the other great Roman basilicas it is aligned west-east, not east-west.
Image: Look and Learn
There is an illustrated online istory of the Archbasilica at Archbasilica of Saint John Lateran and one of the attached Papal Palace at Lateran Palace
Details of some features of the medieval palace can be found in the articles below. However I think that at times they confuse two major public spaces of the palace - the hall built by Pope Leo III in the time of the Emperor Charlemagne, and in which met the Lateran Councils, and which is in the centre of the picture above, and the dining hall, the Triclinium, also built by Pope Leo, which was in the Papal apartments on the left. The articles can be seen in at Rome: Triclinium Leoninum and at Rome: Triclinium Leoninum. There is also a relevant post from the RadTrad about the Lateran complex which can be seen here
In the foreground can be seen the Benediction Loggia added by Pope Boniface VIII ( 1294-1303 ) and which is depicted in the remains of a fresco in St John Lateran and whose complete design is known from copies.
The remains of Giotto’s fresco of Pope Boniface VIII in the Benedction Loggia
The Lateran from the north showing Pope Boniface VIII’s loggia, the Hall of Pope Leo III, the transept facade and to the right the Lateran
A drawing by Maarten Heemskerk (1498-1574)
Image: akg Images
A drawing by Grimaldi showing the medieval palace
Image: Macro Typography blogspot