Gustav Vasa (1496 -1560) was King of Sweden from 1523 until his death. He was the first monarch of the House of Vasa, an influential noble family, which came to be the royal house of Sweden for much of the 16th and 17th centuries. In 1521 he managed to gather a small army in Dalarna and become its leader. He also received help by troops from Leipzig, Germany. By August 1521, the men of Dalarna had elected him regent of Sweden. Two years of war followed, whereby the Danish troops were gradually defeated. He was elected regent in 1521 after leading a rebellion against Christian II of Denmark, the leader of the Kalmar Union who controlled most of Sweden at that time.