Harald III Sigurdsson, also known as Harald the Ruthless, Norwegian Harald Hardråde was born in 1015 and was the King of Norway until his death in 1066.
Due to a family rivalry, King Harold’s (Harold Godwinson) brother Tostig Godwinson, betrayed him and formed an alliance with the King of Norway. Both Tostig and Harald sailed to England in the hope of conquering it - this was almost the last Viking attempt to conquer England!
Unfortunately for them, King Harold was prepared and formed an Army to meet them. The two sides met at Stamford Bridge and on the 25th September the Battle of Stamford Bridge took place.
Harald and Tostig were killed during the battle and so King Harold remained on the throne. It was not long until the second challenge came, but at the other end of the country! Harold had to fight to defend his right to the crown again, this time with a tired army and fewer resources. To make matters worse, he was also fighting a new type of army, one his army had never fought before - see the difference in the Norman and Saxon warfare here.