In 1036 an attempted attack on the south coast by Edward, eldest son of Æthelred II and Emma, failed. A second attempt was made by Edward’s brother, Alfred, but he was captured by Earl Godwine. Alfred was brought before Harold and sentenced to blinding. He died from his wounds.
With Harthacnut detained in Denmark dealing with threats from Norway, Harold was free to be acclaimed king of all England by 1037. Unfortunately, very little is known about his short reign.
Harold died on 17 March 1040 and was the first king buried in Westminster Abbey. When Harthacnut succeeded to the kingdom he had Harold’s body exhumed and thrown into a marsh, possibly as revenge for the death of his half-brother, Alfred.
Essential Facts
Harold I was the son of Cnut and his consort, Ælfgifu.
Harold I became regent, and later king, of England following the death of his father, Cnut.
Harold I was succeeded by his half-brother, Harthacnut.
Timeline
12 November 1035 – Death of Cnut. Harold I became regent of England.
1037 – Harold I became king of England.
17 March 1040 – Death of Harold I.

