events described and well-informed about the events in Poland and Denmark. The assertion that Harald's and Cnut's mother was Bolesław's sister may explain some mysterious statements which appear in medieval chronicles, such as the involvement of Polish troops in invasions of England. Adam of Bremen writes almost a century later that a Polish princess—the sister or daughter of Bolesław I Chrobry of Poland—was the wife of Eric the Victorious and by this marriage the mother of Olof Skötkonung of Sweden, before she became mother of Cnut the Great and Harald II of Denmark in her second marriage with Sweyn. Adam's claims about the marriage to Eric are considered unreliable by many historians, since he is the only source to state this relationship and because he is writing several generations later. The scholia of Gesta Hammaburgensis Ecclesiae Pontificum mentions that it was the Polish king Bolesław who gave the princess' hand in marriage. One problem is that Olof was born at latest in the early 980's, before Boleslaw Chrobry came to power, and therefore was too old to be the unnamed princess's son. Gesta Cnutonis regis mentions in one short passage that Cnut and his brother went to the land of the Slavs, and brought back their mother, who was living there. This does not necessarily mean that his mother was Slavic, but nevertheless this chronicle strongly suggests that she was. The "Liber vitae of the New Minster and Hyde Abbey Winchester" has an entry for a sister of king Cnut named "Santslaue" (Santslaue soror CNVTI regis nostri), which is seen as a Slavic name. Based on this single mention of what would be her daughter and the supposition that the name in question represents the Old Polish name Świętosława found in a later generation of the Polish royal family, J. Steenstrup suggested that this child was named for her mother and hence the Polish wife of Eric and Sweyn was likewise named Świętosława, the name now generally used for her. Bibliography Oswald Balzer, Genealogia Piastów, Kraków 1895. Włodzimierz Dworzaczek, Genealogia, Warsaw 1959 Andrzej Feliks Grabski, Bolesław Chrobry. Zarys dziejów politycznych i wojskowych, Warsaw 1964. Kazimierz Jasiński, Rodowód pierwszych Piastów, Warsaw-Wrocław (1992). References Polish princesses Piast dynasty House of Knýtlinga House of Munsö 10th-century Polish people 11th-century Polish people 10th-century Polish women 11th-century Polish women 10th-century Danish people 11th-century Danish people 10th-century Danish women 11th-century Danish women 10th-century Norwegian people 11th-century