The Basilica of St. John Lateran — in Italian, the Basilica di San Giovanni in Laterano — is the cathedral church of Rome and the official ecclesiastical seat of the Bishop of Rome, who is the Pope. Officially named Archibasilica Sanctissimi Salvatoris ("Archbasilica of the Most Holy Saviour"), it is the oldest and ranks first (being the cathedral of Rome) among the four major basilicas of Rome, and holds the title of ecumenical mother church (mother church of the whole inhabited world) among Roman Catholics.