The Catholic Church, also known as the Roman Catholic Church, is the largest Christian church, with more than 1.2 billion members worldwide.[1] It is one of the oldest religious institutions in the world and has played a prominent role in the history of Western civilisation.[2] The Catholic hierarchy is headed by the Bishop of Rome, known as the Pope. The church's principal doctrines are summarised in the Nicene Creed and the Apostle's Creed; among its distinguishing features are its belief in the supremacy of the Pope and celebration of the seven sacraments.[3]