Askeladd is the commander of a small but powerful Viking band, which owed its success to Askeladd's exceptional intelligence. Ten years before the main Vinland Saga storyline, Askeladd accepted a contract to assassinate Thors, father of Thorfinn. During the Viking invasion and war in England, he manipulated Thorfinn's desire for revenge against him as a way of keeping the gifted young fighter in his service. Askeladd is one of the most skilled fighters in the series, and is particularly adept at predicting his opponents' moves in combat. Askeladd shares the name of Askeladden, a Norwegian folk character known for his cleverness.
He is half-Danish and half-Welsh, being the son of a Welsh princess captured by a Viking raider. He believes in the legend of Avalon, which inspired him to support Prince Canute's bid for kingship of the Danes and ultimately sacrifices himself assassinating King Sweyn in order to install Canute as the Danish King and to ensure the safety of Wales from Denmark.