John, Duke of Östergötland

Who was John, Duke of Östergötland?

John of Sweden, Duke of Östergötland was a Swedish royal dynast. He was titular Duke of Finland 1590–1606 and reigning Duke of Östergötland 1606–18.

His father was John III of Sweden and his mother was Gunilla Bielke. John's half-brother was Sigismund III of Poland and Sweden. His uncle was Charles IX of Sweden, who ruled from 1599 to 1611, and his first cousin was Gustav II Adolf of Sweden.