The Battle of Stiklestad (Slaget på Stiklestad, Stiklarstaðir) in 1030 is one of the most famous battles in the history of Norway. In this battle, King Olaf II of Norway (Óláfr Haraldsson) was killed. During the pontificate of Pope Alexander III, the Roman Catholic Church declared Olaf a saint in 1164.
His younger half-brother, Harald Hardrada (Haraldr Haraldsson harðráði), was also present at the battle. Harald was only fifteen when the battle of Stiklestad took place. He became King of Norway in 1047, until his death in a failed invasion of England at the Battle of Stamford Bridge in 1066.
The authenticity of the battle as a historical event is subject to question. Contemporary sources say the king was murdered. According to the Anglo Saxon Chronicle of 1030, Olaf was killed by his own people. Adam of Bremen wrote in 1070 that Olaf was killed in an ambush, and so did Florence of Worcester in 1100. Those are the only contemporary sources that mention the death of the king. After the king's canonization it was felt that the saint could not have died in such circumstances. The story of the Battle of Stiklestad as most know it gradually developed during the two centuries following the death of King Olaf. Since he was sainted, Olaf must have fallen in a major battle for Christianity.
During the 9th century, Norway was divided between several local kings controlling their own fiefs. By the end of the century, King Harald Fairhair (Old Norse: Haraldr Hárfagri) managed, mainly due to the military superiority gained by his marriage alliance with Hákon Grjótgarðsson of Nidaros, to subjugate these mini–kingdoms, and he created a unified Norwegian state.
This alliance came apart after Harald's death. The jarls of Lade and various descendants of Harald Fairhair would spend the next century interlocked in feuds over power. As well as power politics, religion also played a part in these conflicts, as two of the descendants of Harald Fairhair, Haakon the Good and Olaf Tryggvason attempted to convert the then heathen Norwegians to Christianity.