Otto I, Holy Roman Emperor
Stephen married Gisela, a daughter of Duke Henry the Wrangler of Bavaria, who was a nephew of Otto I, Holy Roman Emperor. Gisela's mother was Gisela of Burgundy, a member of the Welf dynasty. Born around 985, Gisela was younger than her husband, whom she survived. She left Hungary in 1045 and died as Abbess of the Niedernburg Abbey in Passau in Bavaria around 1060.