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.
