According to ecclesiastical tradition, the Basilica of St. John Lateran, in addition to being the bishopric of Rome, is also by far the oldest church in the world.
It was the first large Christian basilica, built in the fourth century AD by Emperor Constantine, who aimed to create a firm basis for imperial power through religion.
The construction of the church also had, therefore, a political motivation and was erected in a place on top of the barracks of the soldiers who had fought for the rival of Emperor Constantine, Maxentius, defeated in the battle of Ponte Milvio. The new basilica served to erase all memory of him and to affirm that the victory of the Emperor had taken place in the sign of Christ, as the legend tells us.
Its structure was to be the model for many other early Christian basilicas, with nave and aisles of extremely different heights, so as to allow the opening of large windows in the walls.
Within a thousand and two hundred years, the Basilica suffered both an earthquake and a fire, which destroyed many of the decorations that the popes had entrusted over the centuries to important artists such as Pisanello, Arnolfo di Cambio and Giotto.
It was only in 1650 that Pope Innocent X commissioned Borromini to rebuild the church as we see it today. The architect concentrated essentially on the nave, where he placed the twelve apostles in marble niches and invited the most active artists of the time to create statues, bas-reliefs and paintings.
He invented many decorations for the side aisles, the pillars and the connections between the various areas of the church. The façade was designed by Alessandro Galilei in 1735, in a style closer to the new classicist trend. Within the ciborium protecting the high altar the relics of the heads of St. Peter and St. Paul are preserved.