Tostig was born around 1026 and died at the Battle of Stamford Bridge 25th September 1066. He was the third son of Earl Godwin of Wessex and the brother of King Harold II. He was created Earl of Northumbria but was exiled after managing the county badly. Angry at being exiled, he allied himself with Harald Hardrada of Norway and invaded England in September 1066.
Family tree for Tostig Godwinson brother of Harold II who was defeated at the Battle of Stamford Bridge showing: