Jarl Sigvaldi was the semi-legendary chieftain of the fabled Jomsvikings and commander of their stronghold - Jomsborg. He succeeded Palnatoke as the leaders of the Jomsvikings in the late 10th century. The character of Sigvaldi remains largely... Wikipedia
Parents: Strut-Harald
Uncle: Harald Bluetooth
Grandparent: Gorm the Old
Nephews: Harald Thorkildsson and Harold (?)
Siblings: Thorkell the Tall
Great-grandparent: Harthacnut I of Denmark
Cousins