Swein Forkbeard was King of Denmark from c. 986 and briefly King of England from December 1013. He was also overlord of Norway c. 986 – c. 994 and from c. 1000. He married the sister of Boleslaus, ruler of Poland, and had three known children by her: King Harald II of Denmark, King Cnut of England, and Estrid, the mother of Sweyn Estridsson, who became king of Denmark in 1047. Swein also had a daughter by an earlier liaison, Gytha, whose son Hakon Eriksson was born in 998. Born: April 22, 963 Died: February 9, 1014 In office: 1013 – February 9, 1014 Wiki link