A Roman necropolis stood on Vatican Hill in pagan times. When a great fire leveled much of Rome in A.D. 64, Emperor Nero, seeking to shift blame from himself, accused the Christians of starting the blaze. He executed them by burning them at the stake, tearing them apart with wild beasts, and crucifying them. Among those crucified was St. Peter, a disciple of Jesus Christ, leader of the Apostles, and the first bishop of Rome, who was supposedly buried in a shallow grave on Vatican Hill.
By the fourth century and official recognition of the Christian religion in Rome, Emperor Constantine began construction of the original basilica atop the ancient burial ground with what was believed to be the tomb of St. Peter at its center. The present basilica, built starting in the 1500s, sits over a maze of catacombs and St. Peter's suspected grave.