The Catholic Church can trace her line of authority through an unbroken chain of succession all the way from Peter, the rock upon which Jesus founded His Church, down to the current Vicar of Christ, Pope John Paul II. In order that the full and living Gospel might always be preserved in the Church, the Apostles left bishops as their successors. The Apostles gave the bishops their own position of teaching authority. We know from inspired Scripture that the apostolic preaching was to be preserved in a continuous line of succession until the end of time. We call it "Apostolic Succession" because the validly ordained bishops in the Catholic Church derive their authority through a direct line of succession passed down to them from the Twelve Apostles.
