St. John Lateran

The Basilica di San Giovanni in Laterano (Basilica of St. John Lateran) is the oldest among the four Papal Basilicas of Rome.
Its full name is Archibasilica Sanctissimi Salvatoris et Sancti Iohannes Baptista et Evangelista in Laterano omnium urbis et orbis ecclesiarum mater et caput.
It dates back to the IV century, when it stood on the Horti Laterani area, which was confiscated and added to the imperial properties during Emperor Nero' reign. Constantine gave the Domus Faustae (as the Basilica was named at the time) to the Bishop of Rome, to thank Jesus Christ for the victory in the Battle of Ponte Milvio in 312 A.D. According to the sources, the original early Christian church known as Basilica Aurea featured five aisles divided by rows of columns and boasted high magnificence, thanks to the several donations by popes and emperors. Charlemagne was baptised in the Basilica in 774 A.D. during Easter Mass.
The Basilica of St. John Lateran changed over the years due to the many refurbishment works ordered by the popes and the contribution of a number of artists who increased the magnificence of the church.
San Salvatore alla Scala Santa is located near the Basilica, the building includes the Scala Sancta (Holy Stairs), wooden steps that encase white marble steps, which, according to Roman Catholic tradition, are the staircase leading once to the praetorium of Pilate in Jerusalem. The steps were taken to Rome by Constantine as a gift for his mother Flavia Giulia Elena. San Giovanni is one of the stops of the procession of  Corpus Christi and boasts two famous relics: the heads of Saint Peter and Saint Paul, kept in the baldaquin in front of the papal altar, as well as a fragment of the table where, as a medieval legend says, Jesus Christ dined during the Last Supper.