Olav Haraldsson (approximately 935-995), St. Olav, was born in Vestfold County and was the great-great grandchild of Harald Hårfagre [Fairhair]. He grew up with his mother Åsta and his stepfather Sigurd Syr, who was also a descendent of the Fairhairs.
When Olav was 12 years of age he went to sea for ten years, first around the Baltic Sea, and later to England. He was in the Danish fleet which attacked London in 1009, which would later put England completely under the rule of the Danish king.
In Norway, Eirik Ladejarl ruled. He was summoned to England to fortify the Danish occupation. Olav now saw his opportunity to aim for the crown of Norway. He returned to Norway in 1015. The Earl of Lade had, however, amassed great goodwill in Trøndelag, where the local chieftains had been left to their own devices without intrusive meddling. Olav was not welcomed with open arms. But he consolidated his position in the south, and ruled as king of the realm from his base in Nidaros [now Trondheim].
From 1017 to 1026 state affairs were fairly quiet and stable. The King travelled around the country formalising the legal and court system pursuant to Christian principles, and established the church as a fundamental power. But he came into conflict with strong families in the districts as they felt their positions were being threatened.
Knut, the Danish King, also wanted to undermine Olav's position, and after a failed operation in the south of Sweden Olav was left in exile with his brother-in-law Prince Jaroslav in Gardarike [the Kingdom of Novgorod, today’s Russia].
Norway had now been given as a fiefdom to Håkon Jarl. But when he died in a shipwreck in 1029, Olav was summoned by his allies. Then he was killed in the battle at Stiklestad [close to Verdal in Nord-Trøndelag], in the middle of the summer of 1030. The outcome of the battle at Stiklestad is a paradox: Popular devotion to the deceased king soon escalated, and the ideas he stood and fought for then had their decisive breakthrough in Norway almost immediately after his death. Pilgrims came from near and far to Olav's grave in Kristkirken [Christ' church], later renamed Nidaros Cathedral, and found comfort and solace there. This was the beginning of the myth of Saint Olav, and Olav Haraldsson's reputation continues to set it's mark on Trondheim into the twenty-first century.
Numerous institutions, places and events are linked to his name.