Rome

Rome, on the Tiber in central Italy, was the capital of the Roman Empire and became one of the principal holy cities of Christianity. Tradition holds that the apostles Peter and Paul were martyred there under Nero after the Great Fire of 64.

Early heterodox teachers were drawn to the capital as well: the Gnostic Valentinus founded a school in Rome around the middle of the second century, and Marcion of Sinope, who distinguished the God of Jesus from the creator of the world, was excommunicated by the Roman church in about 144.

Pope Boniface VIII proclaimed the first Christian Jubilee in 1300, but from 1309 to 1377 the papacy resided at Avignon and Rome fell into neglect; after the Western Schism, Renaissance popes rebuilt the city and began the new Saint Peter's Basilica.