The Tale Of Saint Olaf’s Fiery Conversion Of The Lake Vangsmjøse Region

Despite being posthumously labeled as a saint, King Olaf II of Norway (r. 1015-1028) rarely acted saintly. He gained his title of sainthood due to his unwavering determination to convert the people of Norway to Christianity. Yet, as a former Viking and a conquering king, Saint Olaf had no qualms about opting to convert his subjects by the questionable means of intimidation and violence. Saint Olaf reportedly decided to use such unsaintly tactics against the settlements around Lake Vangsmjøse, located to the northwest of Oslo, where the traditional Norse gods were still worshipped. According to Norwegian-Icelandic folklore, Saint Olaf and his band of warriors trekked in secrecy to the vicinity of Lake Vangsmjøse and, upon arriving in the region, he pulled off an impressive heist, commandeering a majority of the ships owned by the locals living around the lake. After turning the privately-owned ships of Vangsmjøse into his own personal armada in the lake, King Olaf called an assembly of people from the lake-bound towns. From his ships, or just a few steps away from the safety of water, King Olaf offered an ultimatum to the people of the Lake Vangsmjøse region—accept Christianity or face the consequences. Yet, local turnout for the assembly was great, and they reportedly arrived with weapons and no intention to convert. To the credit of both parties, no violence was said to have erupted at the assembly, but neither was any progress made on Olaf’s desired mass-conversion, and this irritated the king. As night approached, King Olaf II halted the assembly and everyone retired for the night. Neither side, however, would sleep peacefully.

As the story goes, both King Olaf and the people of Lake Vangsmjøse were plotting ways to obtain leverage that night. The locals reportedly were bringing in more and more people overnight, pooling all of the inhabitants of the region at the meeting location in order to further overwhelm the king during the next assembly. King Olaf II did not like the way events were unfolding, so he reportedly decided that very night to make the people of Lake Vangsmjøse pay for their hesitance to accept his offer of conversion. As told by Snorri Sturluson (c. 1179-1241) in his Heimskringla—a medieval collection of sagas about the kings of Norway—Saint Olaf decided to row his ships “straight across the lake during the night. There he had his men enter the settlements and burn and plunder, and on the day following they rowed from headland to headland, burning all the settlements” (Snorri Sturluson, Heimskringla, Saint Olaf’s Saga, chapter 121).

At the assembly site, the masses of locals soon saw the smoke billowing from their homes and farms, and they quickly began racing home to put out the fires. Their progress was slow, however, for King Olaf had already stolen their ships. As a result, the locals of Lake Vangsmjøse had to take the long way, running by foot around the lake’s shoreline. When the masses reached the charred and burning homesteads on the far side of the lake, they found the destroyed region suspiciously empty of King Olaf’s warriors. According to Snorri Sturluson, this was because “the king crossed the lake again and burned the countryside on both shores” (Heimskringla, Saint Olaf’s Saga, chapter 121). Therefore, even if the rushing masses had managed to salvage the towns burned in the night and morning, they now would have turned around to see the other side of the lake burning, too.

With many of the villages and farms around the lake smoldering, the locals decided to submit to King Olaf’s demands. Snorri Sturluson continued the tale, writing, “Then the king had all the people baptized and took hostages from the farmers…The king did not much trust the farmers. He had churches built and consecrated, and place priests there to serve them” (Heimskringla, Saint Olaf’s Saga, chapter 121). Following the forced conversion, the installation of priests, the construction of churches, and the taking of hostages, King Olaf II finally left the region.

Written by C. Keith Hansley

Picture Attribution: (Image for the Saga of Harald Hardrada, artwork by Wilhelm Wetlesen (1871-1925), [Public Domain] via Creative Commons).



  • Heimskringla, by Snorri Sturluson and translated by Lee Hollander. Austin: University of Texas Press, 1964, 2018.

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