Estrid Svendsdatter

Estrid Svendsdatter of Denmark (also known as Estrith or Astrith; sometimes called Margaret; fl. 1017–1032; c. 990s – after 1057 and before 1073) was a prominent Danish princess and titular queen of the Jelling dynasty, half-sister of Cnut the Great and wife of the magnate Ulf Jarl. She was the mother of Sweyn II Estridsen, during whose reign she was commonly styled dronning (“queen”) in Denmark, though she was never queen regnant nor a king's consort. Through Estrid, Sweyn traced his claim to the Danish throne and founded the matronymic House of Estridsen ("son of Estrid"), which ruled from 1047 to 1412.

Medieval sources diverge on several points of her life. She was a daughter of Sweyn Forkbeard, but her mother is variously identified in sources as Sigrid the Haughty or, in earlier scholarship, as the Slavic princess sometimes called Gunhild of Wenden, a view now generally rejected. After Sweyn's death in 1014, Estrid came under Cnut's guardianship. He married her to a son of Grand Prince Vladimir the Great or Yaroslav the Wise, but the prince died shortly afterwards. Several western chroniclers, including Rodulfus Glaber and Adam of Bremen, record a proposed or short-lived marriage with the duke of Normandy (probably Robert I, Duke of Normandy), though the precise details remain uncertain. By the early 1020s, she was married to the English magnate Ulf Thorgilsson, who later served as regent in Denmark. By marriage she was thus, successively, a Russian princess, duchess of Normandy and a Danish noblewoman.

Increasing tensions between King Cnut and Jarl Ulf culminated in Ulf's killing at Roskilde in 1026, but Cnut's trust in Estrid was undiminished. Some modern scholars suggest that Estrid may have acquiesced in the act, but sources remain inconclusive. She retained her status and was charged with supporting Harthacnut's rule. As compensation, she received large estates in Scania and on Zealand, making her one of the wealthiest women of her time. Much of this property was granted to Roskilde Cathedral, where she is traditionally credited with replacing its timber church with the first stone church in Denmark. Her later life is scarcely documented, though she evidently supported her son Sweyn II's rise to power, and was praised by Pope Gregory VII.

Estrid is regarded as one of the prominent female figures of the transitional era between the pagan Viking Age and the Christian Middle Ages. Through her son Sweyn II, she re-established the line of descent from Gorm the Old within the Danish royal house, and all subsequent Danish monarchs are descendants of her. She died in the latter half of the 11th century, and was buried as one of the first Danish royals in Roskilde Cathedral.