Olaf II of Norway - Saint Olaf - Wikipedia

Olaf II Haraldsson (995 – 29 July 1030), later known as St. Olaf, was King of Norway from 1015 to 1028. He was canonised at Nidaros (Trondheim) by Bishop Grimkell, one year after his death in the Battle of Stiklestad on 29 July 1030. His remains were enshrined in Nidaros Cathedral, built over his burial site. His sainthood encouraged the widespread adoption of the Christian religion.

The saga of Olav Haraldsson and the legend of Olaf the Saint became central to a national identity. Especially during the period of Romantic Nationalism, Olaf was a symbol of Norwegian independence and pride. Saint Olaf is symbolised by the axe in Norway's coat of arms, and Olsok (29 July) is still his day of celebration. Many Christian institutions with Scandinavian links as well as Norway's Order of St. Olav are named after him.

During his lifetime he was known as Olaf 'the fat' or 'the stout' or simply as Olaf 'the big.' His mother was Åsta Gudbrandsdatter, and his father was Harald Grenske, great-great-grandchild of Harald Fairhair, the first king of Norway. Harald Grenske died when Åsta Gudbrandsdatter was pregnant with Olaf. She later married Sigurd Syr, with whom she had other children including Harald Hardrada, who would reign as a future king of Norway.

In 1019 Olaf married Astrid Olofsdotter, King Olof's illegitimate daughter and the half-sister of his former fiancée. The union produced a daughter, Wulfhild, who married Ordulf, Duke of Saxony in 1042. Numerous royal, grand ducal and ducal lines are descended from Ordulf and Wulfhild, including members of the House of Saxe-Coburg and Gotha. Maud of Wales, daughter of King Edward VII of the United Kingdom, was the mother of King Olav V of Norway, so Olav and his son Harald V, the present King of Norway, are thus descended from Olaf.

But Olaf's success was short-lived. In 1026 he lost the Battle of the Helgeå, and in 1029 the Norwegian nobles, seething with discontent, supported the invasion of King Cnut the Great of Denmark. Olaf was driven into exile in Kievan Rus. He stayed for some time in Sweden in the province of Nerike where, according to local legend, he baptised many locals. In 1029, King Cnut's Norwegian regent, Jarl Håkon Eiriksson, was lost at sea. Olaf seized the opportunity to win back the kingdom, but he fell in 1030 at the Battle of Stiklestad, where some of his own subjects from central Norway took arms against him. The exact position of Saint Olaf's grave in Nidaros has been unknown since 1568, due to the effects of the Lutheran iconoclasm in 1536–37.