OLAF THE HOLY (r. 1015–1030), ruler of Norway and Scandinavia's first saint. A missionary king who strove to impose religious unity on Norway, Olaf had great influence on the practice of traditional religion in Norway and Iceland. Olaf (also called Olaf the Stout and Saint Olaf) was a descendant of Harald I (known as Fairhair). He became a Viking at a young age, harrying ships in the Baltic and then off the coast of England. Later he fought for the duke of Normandy. Spurred by a prophetic dream, Olaf began his return to Norway to become king, stopping on the way to spend the winter of 1013–1014 in Rouen, where he was baptized.

In 1028 Olaf was forced to flee Norway because of conflicts with powerful Norwegian chieftains who were allied with the Danish king, Knut. While in exile he had another dream: that it was God's...