Pope Martin V (Latin: Martinus V), born Otto (or Oddone) Colonna, was Pope from 11 November 1417 to his death in 1431. His election effectively ended the Western Schism (1378-1417).
After deposing Antipope John XXIII in 1415, the Council of Constance was long divided by the conflicting claims of Pope Gregory XII (1406-15) and Antipope Benedict XIII (1394-1423). Martin was elected pope, at the age of 48, at the Council of Constance on St. Martin's Day, 11 November 1417, by a conclave consisting of twenty-three cardinals and thirty delegates of the council. He was ordained a priest on Saturday November 13, 1417 and consecrated bishop the next day.
When the second Pope to take the name Martin was elected in 1281, there was confusion over how many Popes had taken the name before. It was believed then that there were three, so the new Pope of 1281 became Martin IV. But, in reality, those believed to be Martin II and Martin III were actually named Marinus I and Marinus II, although they are sometimes still referred to as "Martin II" and "Martin III". This has advanced the numbering of all subsequent Popes Martin by two. Popes Martin IV-V were actually the second and third popes by that name.
Martin V died in Rome of a stroke on 20 February 1431 at the age of 62. He is buried at St. John Lateran Basilica.