Ivar and Ubba are identified as the commanders of the Danes, and the killers of Edmund, and it is unknown what part, if any, Halfdan took.

Following the conquest of East Anglia, Ivar apparently left the Great Heathen Army - his name disappears from English records after 870. However, he is generally considered to be identical to Ímar, a Norse King of Dublin who died in 873. With Ivar