Osbeorn Bulax's father governed on what king's behalf?
Siward, Earl of Northumbria Siward or Sigurd ( or more recently ; Old English: "Sigeweard") was an important earl of 11th-century northern England. The Old Norse nickname "Digri" and its Latin translation "Grossus" ("the stout") are given to him by near-contemporary texts. Siward was probably of Scandinavian origin, perhaps a relative of Earl Ulf, and emerged as a powerful regional strongman in England during the reign of Cnut ("Canute the Great", 1016–1035). Cnut was a Scandinavian ruler who conquered England in the 1010s, and Siward was one of the many Scandinavians who came to England in the aftermath of that conquest. Siward subsequently rose to become sub-ruler of most of northern England. From 1033 at the latest Siward was in control of southern Northumbria, that is, present-day Yorkshire, governing as earl on Cnut's behalf.
Harald III of Denmark Harald III (Harald the Whetstone, Danish: "Harald Hen" ;  1040 – April 17, 1080) was King of Denmark from 1076 to 1080. Harald III was an illegitimate son of Danish king Sweyn II Estridsson, and contested the crown with some of his brothers. He was a peaceful ruler who initiated a number of reforms. Harald was married to his cousin Margareta Hasbjörnsdatter, but did not leave any heirs, and was succeeded by his brother Canute IV the Saint. Four of his half-brothers were in turn crowned Danish kings.