Antipope

An antipope (Latin: antipapa) or anti-pope is a person who, in opposition to the one who is generally seen as the legitimately elected Pope, makes a significantly accepted competing claim to be the Pope, the Bishop of Rome and leader of the Catholic Church. At times between the 3rd and mid-15th century, antipopes were supported by a fairly significant faction of religious cardinals and secular kings and kingdoms. Persons who claim to be pope, but have few followers, such as the modern sedevacantist antipopes, are not classified with the historical antipopes.