Enrique III el Negro
The marriage agreement between Gunhilda of Denmark (sister of Harthacnut) and Henry III, Holy Roman Emperor would allow descendants of this marriage to claim the throne of Denmark and potentially of England. The marriage, from Henry's perspective, was probably orchestrated to allow the Holy Roman Empire to claim control of Denmark and the western areas of the Baltic Sea. However, Gunhilda died in 1038 with no known sons. Her only daughter was Beatrice I, Abbess of Quedlinburg, who never married.