King of Denmark and Norway (1448–81) and Sweden (1457–64), who founded the Oldenburg dynasty. Elected to power by the Danish Rigstad and confirming his status by marriage to his predecessor’s widow, he gained the Swedish throne after the war of 1451–57, but lost control to the Swedish nobility later. He also gained Schleswig and Holstein and was at war with England (1469–74). Strongly Catholic, he founded the Catholic University of Copenhagen in 1479.