
Kattegat was a Scandinavian city and petty kingdom during the Viking Age. Located in southern Norway along the Kattegat Strait, it was the seat of the Thing council and the Earl of Kattegat. The city came under the rule of Ragnarr Lodbrok during the early 9th century, and it was contested by his family after his death in 867. Ivar the Boneless seized Kattegat from Lagertha with the aid of Frankish troops from his uncle Rollo Sigurdsson, and he reigned as king for just a year before Lagertha's son Bjorn Ironside seized power. In 1002, Kattegat was the launching point for Sweyn Forkbeard's Danish conquest of England following the St. Brice's Day massacre.