The Story of Norway by Hjalmar Hjorth Boysen

King Olaf's first endeavor, after having ascended the throne, was to Christianize the country. He was by nature well adapted for this task, being zealous in the faith, resolute, and uncompromising. Where gentle means did not avail he had no hesitation in employing sword and fire. Vehement as he was by temperament, brooking no argument, he wasted no time in weighing the probabilities of success or failure, but in the conviction of the sanctity of his cause stormed resistlessly onward and by his impetuosity and ardor, bore down all opposition. His first appearance as the champion of the new religion was in Viken, where he called his relations and adherents together and told them, that it was his intention to convert the whole kingdom of Norway to faith in Christ the White, even though he were to lose his life in the attempt. In Viken lived at that time his mother and his step-father, Lodin, who had a large following of friends and relations.

Some of these were, no doubt, already Christians, or had been _primsigned_, as Christianity had, twenty-five years before, been preached for a short time in this part of the country by two Germans. No particular opposition was therefore offered to the king's command, and within a brief period Olaf had the satisfaction of seeing all of Viken -- the old kingdom of his father, Tryggve -- nominally, at least, converted to Christianity. It is not to be inferred, however, that the converts, in accepting baptism, renounced their faith in the gods whom they had previously worshipped. On the contrary, they continued to believe in their existence, and perhaps even secretly to worship them.