The doctrine of Petrine supremacy is a Catholic belief that Jesus Christ gave the apostle Peter authority on Earth to lead his church and that this supreme spiritual authority is passed on to the pope. Under certain circumstances, the pope, as Peter's successor, is considered infallible.
According to the Bible, Peter's original name was Simon. Jesus gave him the name Peter, which in Aramaic was Cephas, meaning "rock." In chapter 16 of the book of Matthew in the New Testament, Jesus says, "Thou art Peter, and upon this rock I will build my church, and the gates of hell shall not prevail against it." Catholics use this statement to justify the authority of Peter and his successors. A further justification is in the book of John chapter 21, where Jesus says to Peter, "Feed my sheep."
According to the book of the Acts of the Apostles in the Bible, when Jesus ascended into heaven, Peter took over leadership of his apostles and other followers. In secular history, though he never officially assumed the title of the bishop of Rome, Peter was recognized as the first pope. Every subsequent pope was recognized not as the successor of the pope that went before but as the successor of Peter. In 1870, 433 bishops at the First Vatican Council reinforced this doctrine when they issued the decree of papal infallibility. This stated that in matters of faith and morals, the pope has supreme authority, and his word cannot be questioned.