 Tryggve the Pretender came with an army from England.He said he was the son of Olav Tryggvason and therefore claimed the kingdom as his own.When word reached Sveinn Alfífuson and Aelgifu that Tryggve's invasion was imminent, they summoned the landholders of Halogaland and the Trondheim district to join the royal army in resisting Tryggve.