 However, their men eventually killed Erlend during a raid on the island of Damsay on the night of 21 December 1154.The primary source for information about Erlend's life is the "Orkneyinga saga", which was first compiled in Iceland in the early 13th century.Much of the information it contains about the early period of Norse history in Orkney is "hard to corroborate" although the proximity of Erlend's "floruit" to the time when this Norse saga was compiled in written form may lend weight to its authenticity with respect to this period.