One of the books of the Bible, called the Acts of the Apostles, tells what happened to the disciples of Jesus after he was put to death by crucifixion in the 1st century AD. One of his twelve disciples became the leader. His name was Simon Peter and he was a fisherman from Galilee. Peter became one of the most important people in starting the Christian Church. Another important disciple was Paul of Tarsus, who travelled to many places and wrote lots of letters to teach and to encourage people in the new Christian groups that began to spring up in many different parts of the Roman Empire. St. Paul travelled to Rome. It is believed that St. Peter also travelled to Rome and that both Paul and Peter were put to death there as Christian martyrs. St. Paul was beheaded with a sword. Peter was crucified up-side-down. It is believed that the body of St. Peter was buried in a cemetery near the Via Cornelia, a road leading out of the city, on the hill called Vaticanus. Peter's grave was marked, by a red rock, the symbol of his name. The place where Peter died was marked, in the 1400s, by a little round temple called the "Tempietto" designed by Bramante.