Harold was born in 1016 (exact date not known) and died 17th March 1040. He was the second son of King Cnut the Great by his first wife, Aelfgifu of Northampton. He took the throne of England as King Harold I in 1035 when the nominated successor, Harthacnut, was unable to return to England due to problems in Denmark. When he died Harthacnut took the throne.
Family tree for King Harold I, son of King Cnut the Great, showing: