The extended name of the church cathedral of Rome is Arcibasilica Papale e Cattedrale del Santissimo Salvatore e dei Santi Giovanni Battista ed Evangelista in Laterano (Patriarchal Arcibasilica and Cathedral of the Holy Saviour and of the Saints John the Baptist and the Evangelist in Lateran). 

It rises on the same spot where Constantine built a basilica around 314 on grounds that already belonged to the noble family of the Laterani, from which the entire area took its name. 

The current church follows the general lines of the plan of the original basilica with its five naves (like the original church of St. Peter’s) and for almost one thousand years from its foundation to the Avignonese period it was the most important church of Christianity, the centre of the Pope’s power and his residence. 

The basilica was repeatedly damaged and restored, and enriched in the course of the centuries. Nicholas the Fourth commissioned the mosaic in the apse to Jacopo Torriti (1289-1291), Boniface the Eighth built the Loggia delle Benedizioni (Loggia for Blessings) for the jubilee in 1300, which was restructured in its current appearance at the end of the sixteenth century, Martin the Fifth commissioned the decoration of the interior with frescoes Gentile da Fabriano and Pisanello(1431-1432), Sixtus the Fifth  replaced the Loggia delle Benedizioni with the current one (damaged by an attempt in 1993), Clement the Eighth decorated the transept (1599-1600). 

In view of the jubilee in 1650 Innocent the Tenth Pamphili commissioned the reconstruction o fthe interior to Francesco Borromini, maintaining the overall plan with five naves and the very rich sixteenth century lacunar ceiling in the central nave. The great Ticinese architect intervened twice: between 1645 and 1650 he remodelled the interior, in the years 1656-57 he fixed the floor and reassembled in his baroque style the fragments of the ancient funerary monuments he had removed. 

The current facade was built between 1732 and 1735 under Pope Clement the Twelfth Corsini according to a plan by Alessandro Galilei, and lastly between 1884 and 1886 the presbytery and apse were completely redone, causing the loss of the original mosaic by Torriti which was replaced with a faithful copy by Vespignani. 

The eighteenth century facade by Galilei presents a single giant order of pilasters and Corinthian semicolumns, a central tympanum and a balustrade crowned by fifteen colossal statues representing Christ, Saint John the Baptist and the Evangelist and the Doctors of the Church. 

A long inscription on the large cornice commemorates the building of the facade commissioned by Clement the Twelfth, whose coats of arms (Corsini) appear below on the stylobate. 

Marble high reliefs representing Stories of the life of the Baptist and a statue of Constantine (fourth century AD) coming from the baths (thermae) on the Quirinal Hill are in the portico. The central door has precious wings that come from the Curia (Senate House) in the Forum Romanum. The last door on the right is the Holy Door. The interior appears in the splendid seventeenth century arrangement planned by Borromini. 

The central nave still presents the sixteenth century ceiling (perhaps designed by Pirro Ligorio) that Borromini wanted to eliminate, with twelve aedicules each with green columns and a tympanum, decorated with the dove symbol of the Pamphilj family that host twelve statues of apostles. The niches are surmounted by stucco high reliefs by Alessandro Algardi. 

The beautiful ogival tabernacle by Giovanni di Stefano (1367) stands at the end of the nave with the papal altar beneath, where only the Pope can serve mass. At its base stands the tomb of Pope Martin the Fifth, work by Simone Ghini (1443). The transept is one of the most representative complexes of the end of sixteenth century Roman Mannerism with works by various painters, including Cavalier d’Arpino, Cesare Nebbia, Orazio Gentileschi, and Giovanni Baglione. 

Borromini expressed his ornamental fancy and talent freely in the side naves, by placing the ancient funerary monuments between the chapels and on the inner face of the pillars, using them as purely ornamental items according to the taste of the time. In the right middle nave there is a fragment of a fresco coming from the decoration of the original Loggia delle Benedizioni, attributed to various authors (by some scholars to Giotto, by others to Cavallini). 

The copy of lying statue of Riccardo degli Annibaldi by Arnolfo di Cambio in 1276 catches the eye in the far left nave (the original statue is in the cloister). Both the museum that keeps precious vestments, altar cloths and holy vessels, and the cloister, masterpiece of the Cosmati art, where architectural elements, sculptures and ornaments of the ancient basilica are kept, certainly deserve to be visited.