In the Roman Catholic Church, an Episcopal Conference, Conference of Bishops, or National Conference of Bishops is an official assembly of all the bishops of a given territory. Episcopal conferences have long existed as informal entities, over forty existing before the Second Vatican Council. They were first established as formal bodies by the Second Vatican Council (Christus Dominus, 38), and implemented by Pope Paul VI's 1966 motu proprio Ecclesiae sanctae. The operation, authority, and responsibilities of episcopal conferences are currently governed by the 1983 Code of Canon Law (see especially canons 447-459].