Sveinn I of Hordaland (The Kalmar Union)

Sveinn I Haakonsson, (or Sweyn I), succeeded his father as Regent-King of Hordaland. However instead of owing fealty to Denmark as his father had done, his allegiance was with Svealand, specifically Olof I who had been rewarded for his participation in the Battle of Svolder.

Supporting Sweyn Forkbeard's war against Olaf II of Viken Olof I was rewarded with extensive lands in Hordaland thereby taking over Denmark's overlordship. He would help prop up Sveinn's faltering regency until civil war overtook the kingdom. He also gave him a relative in marriage, Hólmfríðr, who was possibly his sister.

Sveinn's elder half-brother Eirik, Earl of Lade, went to England with Sweyn Forkbeard during the Danish invasions and from 1012 Sveinn co-ruled Lade and Hordaland with his nephew Harald Eiriksson.

In 1015 Olaf Haraldsson, a distant but direct descendant of Harald Fairhair returned to Hordaland claiming his birthright after twenty years acting out the typically violent life of a viking. He immediately received the support of several petty kings eager to shrug off both Svealandic and Ladish rule. Clashing at the sea battle of Primsigð Olaf proved victorious.

Sveinn would retreat to Svealand but would die there before he had the opportunity to muster a force to retake the kingdom.