
Kjartan and Sven then retaliated against Ragnar by burning Ragnar, his father Ravn, and his wife Sigrid to death at their great hall in Leeds, and Ragnar's adoptive son Uhtred of Bebbanburg set out to avenge his death. He then pillaged several monasteries and nunneries as punishment for the imagined revolt, and the new ruler of Northumbria, Ricsige, rewarded Kjartan by making him his chief warrior and tax collector. In 871, however, Kjartan created rumors that Ecgberht had been encouraging Anglo-Saxon revolts, causing Ecgberht to lose popularity and flee to the court of Burghred of Mercia in the south. Kjartan went on to become the commander of King Ecgberht I of Northumbria's household troops, ensuring that he remained loyal to the Danes. In 866, he took part in the invasion of Northumbria, but he was banished from Ragnar's lands in Northymbre after his son Sven Kjartansson attempted to rape Ragnar's daughter Thyra Ragnarsdottir. Kjartan was a Danish Viking ship captain under Earl Ragnar. In 880, he was killed by Ragnar's son Ragnar Ragnarsson at the Battle of Dunholm. Kjartan seized power from Earl Ragnar the Fearless in 871, killing him in an act of revenge for having banished him and his son Sven Kjartansson. Kjartan the Cruel (died 880) was a Danish Viking earl who ruled over County Durham in England during in 9th century.
