Antipope Alexander V

https://en.wikipedia.org/wiki/Antipope_Alexander_V

Peter of Candia, also known as Peter Phillarges (c. 1339 – May 3, 1410), named as Alexander V (Latin: Alexander PP. V; Italian: Alessandro V), was an antipope elected by the Council of Pisa during the Western Schism (1378–1417). He reigned briefly from June 26, 1409 to his death in 1410, in opposition to the Roman pope Gregory XII and the Avignon antipope Benedict XIII. In the 20th century, the Catholic Church reinterpreted the Western Schism by recognizing the Roman popes as legitimate. Gregory XII's reign was extended to 1415, and Alexander V is now regarded as an antipope.