Sweyn II Estridsson (Old Norse: Sveinn Ástríðarson, Danish: Svend Estridsen) (c. 1019 – 28 April 1074 or 1076) was King of Denmark from 1047 until his death in 1074. He was the son of Ulf Jarl and Estrid Svendsdatter. He was married three times, and fathered 20 children or more, including the five future kings Harald III Hen, Canute IV the Saint, Oluf I Hunger, Eric I Evergood and Niels out of wedlock.