Estrid Svendsdatter of Denmark (Estrith, Astrith: 990/997 – 1057/1073), was a Danish princess and titular Queen, a Russian princess and, possibly, Duchess of Normandy by marriage. She was the daughter of Sweyn Forkbeard and perhaps Gunhild of Wenden and sister of Cnut the Great. By Ulf Jarl, she was the mother of the later King Sweyn II Estridson and Beorn Estrithson. The dynasty that ruled Denmark in 1047–1412 was named after her. She was known in Denmark as Dronning Estrid, (Queen Estrid), despite the fact that she was not married to a King and not a queen regnant.