<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The Catholic Church, also known as the Roman Catholic Church, is the largest Christian church, with more than 1.299 billion members worldwide . As one of the oldest religious institutions in the world, it has played a prominent role in the history and development of Western civilisation . The church is headed by the Bishop of Rome, who is known as the Pope . The church's doctrines are summarised in the Nicene Creed . Its central administration, the Holy See, is in the Vatican City, an enclave within Rome, Italy . </P> <P> The Catholic Church teaches that it is the One, Holy, Catholic and Apostolic church founded by Jesus Christ, that its bishops are the successors of Christ's apostles, and that the Pope is the successor to Saint Peter to whom primacy was conferred by Jesus Christ . It maintains that it practises the original Christian faith, reserving infallibility, passed down by sacred tradition . The Latin Church, the Eastern Catholic Churches, and institutes such as mendicant orders and enclosed monastic orders reflect a variety of theological and spiritual emphases in the church . </P>

Which title is used for the leader of the roman catholic church