Latin Christianity, also known as Roman Christianity, is one of the original denominations of Christianity and the largest Catholic denomination, centered around Rome, one of the cities of the Christian Pentarchy (also including Constantinople, Alexandria, Antioch, and Jerusalem). The Latin Church was led by the Holy See in Rome, headed by the Pope (the successor of Saint Peter as Bishop of Rome), and it was distinguished from Greek Christianity and Eastern Christianity in that it used Latin as its liturgical language and was centered in Latin-speaking Western Europe. Following the Council of Chalcedon in 451 AD, several Eastern Christian churches split from the Latin Church, with Nestorianism, Miaphysitism, and Eastern Orthodoxy breaking communion with the Latin Church over the next several centuries. The Latin Church was known for its sacred tradition and seven sacraments (baptism, confirmation, Eucharist/communion, reconciliation, anointing the sick, holy orders, and matrimony), as well as for its catechism, a set of the Church's teachings and doctrines which all adherents were bound to follow. In 1964, amid the Vatican II council, the Church instructed its parishes to read the epistle and gospel from the Mass of the day in the vernacular, and the pontifical universities in Rome stopped teaching Latin in 1967. However, the revised Roman Rite of 1969 and 2002 remains the main liturgical rite of the Latin Church, partially retainig its traditional Latin character. Today, the Latin Church is the largest denomination of Catholicism, having over 1 billion adherents; there are 16 million "Eastern Catholics".