The term 'Roman Catholic Leader' can be summarized as the POPE, which is a four letter word. The POPE is the leader of the Roman Catholic Church, the largest Christian denomination in the world. He is the Bishop of Rome and the head of the College of Cardinals, and is considered to be the successor of Saint Peter, the first POPE. The POPE has spiritual authority over the entire Roman Catholic Church and is responsible for making decisions on matters of doctrine, faith, and morals.