In his youth he took part in Viking raids, journeying eastwards as well as to the west, both the Baltic region and England. It was on such voyages that he became familiar with Christianity, and he was probably baptized in Rouen, France, in about 1013. Most Norwegians had probably converted to Christianity before Olav Haraldsson`s time, but he acted as a missionary king in certain parts of the country, and the Norwegian Church was founded in his time.In 1028, he had to flee east to what is now Russia,and he fell at Stiklestad when he tried to regain the kingdom two years later.
OlavHaraldsson`s reign appears to have lasted about a decade. He defeated the earls of Lade who ruled Trøndelag at the time, as well as other chieftans. Other pledged their allegiance to him more or less voluntarily. From the middle of the 1020 however,the situation changed. King Canute of Denmark and England gradually won the allegiance and many of the king`s opponents in Norway. Finally this alliance became too powerful for King Olav, who was forced to flee in 1028.