The Archbasilica of Saint John Lateran (officially the Major Papal, Patriarchal and Roman Archbasilica, Metropolitan and Primatial Cathedral of the Most Holy Savior and Saints John the Baptist and the Evangelist in Lateran, Mother and Head of All Churches in Rome and in the World), commonly known as the Lateran Basilica or Saint John Lateran, is the Catholic cathedral of the Diocese of Rome in the city of Rome, Italy. It serves as the seat of the bishop of Rome and head of the worldwide Catholic Church: the pope. The only "archbasilica" in the world, it lies outside of Vatican City proper, which is located approximately four kilometres (2+1⁄2 miles) northwest. Nevertheless, as properties of the Holy See, the archbasilica and its adjoining edifices enjoy an extraterritorial status from Italy, pursuant to the terms of the Lateran Treaty of 1929. Dedicated to Christ the Saviour, in honor of John the Baptist and John the Evangelist, the place name – Laterano (Lateran) – comes from an ancient Roman family (gens), whose palace (domus) grounds occupied the site. The adjacent Lateran Palace was the primary residence of the pope until the Middle Ages.
The church is the oldest of the four major papal basilicas, and it is one of the Seven Pilgrim Churches of Rome. Founded in 324, it is the oldest public church in the city of Rome, and the oldest basilica in the Western world. It houses the cathedra of the Roman bishop, and it has the title of ecumenical mother church of the Catholic faithful. The building deteriorated during the Middle Ages and was badly damaged by two fires in the 14th century. It was rebuilt in the late 16th century during the reign of Pope Sixtus V. The new structure's interior was renovated in the late 17th century, and its façade was completed in 1735 under Pope Clement XII.
The current Rector is Cardinal Archpriest Baldassare Reina, Vicar General for the Diocese of Rome since 6 October 2024. The president of the French Republic, currently Emmanuel Macron, is ex officio the "First and Only Honorary Canon" of the archbasilica, a title that the heads of state of France have possessed since King Henry IV.
The large Latin inscription on the façade reads: Clemens XII Pont Max Anno V Christo Salvatori In Hon SS Ioan Bapt et Evang. This abbreviated inscription translates as: "The Supreme Pontiff Clement XII, in the fifth year [of his Pontificate, dedicated this building] to Christ the Saviour, in honor of Saints John the Baptist and [John] the Evangelist". Because Christ the Saviour is its primary dedication, its titular feast day is 6 August, the Transfiguration of Christ.
The archbasilica's Latin name is Archibasilica Sanctissimi Salvatoris ac Sancti Ioannis Baptistae et Ioannis Evangelistae ad Lateranum, which in English is the Archbasilica of the Most Holy Savior and Saints John the Baptist and John the Evangelist at the Lateran, and in Italian Arcibasilica [Papale] del Santissimo Salvatore e Santi Giovanni Battista ed Evangelista in Laterano.
The archbasilica stands over the remains of the Castra Nova equitum singularium, the "New Fort of the Roman imperial cavalry bodyguards". The fort was established by Septimius Severus in AD 193. Following the victory of Emperor Constantine the Great over Maxentius (for whom the Equites singulares augusti, the emperor's mounted bodyguards, had fought) at the Battle of the Milvian Bridge, the guard was abolished and the fort demolished. Substantial remains of the fort lie directly beneath the nave.
The remainder of the site was occupied during the early Roman Empire by the palace of the gens Laterani. Sextius Lateranus was the first plebeian to attain the rank of consul, and the Laterani served as administrators for several emperors. One of the Laterani, Consul-designate Plautius Lateranus, became famous for being accused by Nero of conspiracy against the Emperor. The accusation resulted in the confiscation and redistribution of his properties.
The Lateran Palace fell into the hands of the Emperor when Constantine the Great married his second wife Fausta, sister of Maxentius. Known by that time as the Domus Faustae or "House of Fausta", the Lateran Palace was eventually given to the Bishop of Rome by Constantine the Great during the pontificate of Pope Miltiades, in time to host a synod of bishops in 314 that was convened to challenge the Donatist schism, declaring Donatism to be heresy. The palace basilica was converted and extended, becoming the residence of Pope Sylvester I, eventually becoming the Cathedral of Rome, the seat of the Popes as the Bishops of Rome.
Pope Sylvester I presided over the official dedication of the archbasilica and the adjacent Lateran Palace in 324, changing the name from Domus Fausta to Domus Dei ("House of God"), with a dedication to Christ the Savior (Christo Salvatori). When a cathedra became a symbol of episcopal authority, the papal cathedra was placed in its interior, rendering it the cathedral of the Pope as Bishop of Rome. When Gregory the Great sent the Gregorian mission to England under Augustine of Canterbury, some original churches in Canterbury took the Roman plan as a model, dedicating a church both to Christ as well as one to Saint Paul, outside the walls of the city. The church name "Christ Church", so common for churches around the world today in Anglophone Anglican contexts, originally came from Canterbury's Cathedral of Christ, which was named after St. John Lateran's original name.
The anniversary of the dedication of the church has been observed as a feast since the 12th century, with 9 November as the feast.
On the archbasilica's front wall between the main portals is a plaque inscribed with the words SACROS LATERAN ECCLES OMNIUM VRBIS ET ORBIS ECCLESIARVM MATER ET CAPVT ("Most Holy Lateran Church, mother and head of all the churches in the city and the world"); a visible indication of the declaration that the basilica is the "mother church" of all the world. In the twelfth century the canons of the Lateran claimed that the high altar housed the Ark of the Covenant and several holy objects from Jerusalem. The basilica was thus presented as the Temple of the New Covenant.
The archbasilica and Lateran Palace were re-dedicated twice. Pope Sergius III dedicated them in honor of Saint John the Baptist in the 10th century, occasioned by the newly consecrated baptistry of the archbasilica. Pope Lucius II dedicated them in honor of John the Evangelist in the 13th century. Thus, Saint John the Baptist and Saint John the Evangelist became co-patrons of the archbasilica, while the primary Titular is still Christ the Savior, as the inscription in the entrance indicates and as is traditional for patriarchal cathedrals. Consequently, the archbasilica remains dedicated to the Savior, and its titular feast is the Feast of the Transfiguration of Christ on 6 August. The archbasilica became the most important shrine of the two Saint Johns, albeit infrequently jointly venerated. In later years, a Benedictine monastery was established in the Lateran Palace, and was devoted to serving the archbasilica and the two saints.
Every pope, beginning with Pope Miltiades, occupied the Lateran Palace until the reign of the French Pope Clement V, who in 1309 transferred the seat of the papacy to Avignon, a papal fiefdom that was an enclave in France. The Lateran Palace has also been the site of five ecumenical councils (see Lateran councils).
During the time the papacy was seated in Avignon, France, the Lateran Palace and the archbasilica deteriorated. Two fires ravaged them in 1308 and 1362. After both fires the pope sent money from Avignon to pay for their reconstruction and maintenance. Nonetheless, the archbasilica and Lateran Palace lost their former splendor. When the papacy returned from Avignon and the pope again resided in Rome, the archbasilica and the Lateran Palace were deemed inadequate considering their accumulated damage. The popes resided at the Basilica di Santa Maria in Trastevere and later at the Basilica di Santa Maria Maggiore. Eventually, the Palace of the Vatican was built adjacent to the Basilica of Saint Peter, which existed since the time of Emperor Constantine I, and the popes began to reside there. It has remained the official residence of the pope ever since, though Pope Francis chose to reside in the Domus Sanctae Marthae in the Vatican City, not in the Papal apartments.