Sigurd Eysteinsson - Heimskringla and Orkneyinga

Heimskringla and Orkneyinga

The two main sources for Sigurd's life are the Norse Heimskringla and Orkneyinga sagas. According to the sagas, after the Battle of Hafrsfjord unified the Norwegian kingdom in or after 872, the Orkney and Shetland islands became a refuge for exiled Vikings, who raided their former homeland. The king of Norway, Harald Finehair, subdued the pirate Vikings with the aid of Rognvald Eysteinsson of Møre.

During the conquest, Rognvald's son, Ivar, was killed, and in compensation for his loss Harald gave Rognvald the islands along with the title of Jarl or Earl. With the consent of Harald, Rognvald transferred the title and lands to his brother Sigurd, who was one of Harald's forecastlemen. The Historia Norvegiæ, written around the same time as the sagas but from a different source, corroborates the conquest of the islands by Rognvald's family, but omits any details.

In league with Thorstein the Red, Sigurd expanded his domains to the Scottish mainland, and conquered Caithness and Sutherland at least as far south as Ekkjalsbakka, which some sources say was in Moray, but was much more likely to be farther north somewhere along the banks of the river Oykel. His exploits in conquering the north of Scotland became legendary and earned him the epithet, "the Mighty", or in Old Norse ríki.