Who was the half-brother of Sweyn Haakonsson that participated in the conquest of English by King Canute the Great?
Sweyn Haakonsson Sweyn Haakonsson (Old Norse: "Sveinn Hákonarson", Norwegian: "Svein Håkonsson" ) (died c. 1016) was an earl of the house of Hlaðir and co-ruler of Norway from 1000 to c. 1015. He was the son of earl Hákon Sigurðarson. He is first mentioned in connection with the battle of Hjörungavágr, where the "Heimskringla" says he commanded 60 ships. After the battle of Svolder in the year 1000, Sveinn became co-ruler of Norway with his half-brother, Eiríkr Hákonarson. After Eiríkr went to England in 1014, Sveinn was co-ruler with Hákon Eiríksson. In 1015, Óláfr Haraldsson arrived in Norway and claimed the throne. He defeated Sveinn and his allies in the battle of Nesjar. Sveinn retreated to Sweden, intending to muster a force to retake Norway but he died of an illness before he could return.
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.