Christian II (1481 – 1559). Scandinavian monarch under the Kalmar Union. He reigned as King of Denmark and Norway from 1513 until 1523 and of Sweden from 1520 until 1521. From 1513 to 1523, he was concurrently Duke of Schleswig and Holstein in joint rule with his uncle Frederick. He married Isabella of Austria. Sweden secessed from the Kalmar Union thanks to Gustav Vasa.