The head of the worldwide Roman Catholic Church, comprising of some 1.3 billion adherents. He resides in the Vatican City, an independent city state of Rome, Italy. The pope is considered one of the world's most powerful people due to the extensive diplomatic, cultural, and spiritual influence of his position with members revering him as a divine authority, with his spiritual directives often given undue or unquestioning allegiance. 

See also: Roman Catholicism.