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.
Harald Hardrada Harald Sigurdsson (Old Norse: "Haraldr Sigurðarson" ;  1015 – 25 September 1066), given the epithet Hardråde ("harðráði ", roughly translated as "stern counsel" or "hard ruler") in the sagas, was King of Norway (as Harald III) from 1046 to 1066. In addition, he unsuccessfully claimed the Danish throne until 1064 and the English throne in 1066. Prior to becoming king, Harald had spent around fifteen years in exile as a mercenary and military commander in Kievan Rus' and of the Varangian Guard in the Byzantine Empire.