1318 – 15 October 1389), born Bartolomeo Prignano (Italian pronunciation: [bartolo'm??o pri?'?a?no]), was head of the Catholic Church and ruler of the Papal States from 8 April 1378 to his death in 1389.
He was the most recent pope to be elected from outside the College of Cardinals.
His reign, which began shortly after the end of the Avignon Papacy, was marked by immense conflict between rival factions as part of the Western Schism.