GUSTAVUS I. king of Sweden, son of Eric de Vasa duke of Gripsholm. Christian II. king of Denmark having made himself master of the kingdom of Sweden, confined Gustavus at Copenhagen; but he making his escape, wandered a long time in the forests, till the cruelties of the tyrant having occasioned a revolution, he was first declared governor of Sweden, and in 1513 elected king. This prince introduced Lutheranism into his dominions, which in a little time spread itself all over the kingdom. He died in 1560; having made his kingdom hereditary, which was before elective. See SWEDEN.