Who was the half-brother of Sweyn Haakonsson that participated in the conquest of English by King Canute the Great?
Eiríkr Hákonarson Eric Haakonsson (960s – 1020s) was Earl of Lade, Governor of Norway and Earl of Northumbria. He was the son of Earl Hákon Sigurðarson and brother of the legendary Aud Haakonsdottir of Lade. He participated in the Battle of Hjörungavágr, the Battle of Svolder and the conquest of England by King Canute the Great.
William Adelin William Ætheling (] ; 5 August 1103 – 25 November 1120), designated or titled Adelin (alternately rendered as "Adelinus", "Adelingus", "A(u)delin" or other Latinised Norman-French variants of "Ætheling"), was the son of Henry I of England by his wife Matilda of Scotland, and was thus heir apparent to the throne. His early death without issue caused a succession crisis, known in history as The Anarchy.