Wikipedia
Kolgrim, also spelled Kollgrim or Kolgrimr, (d. 1407 in Gardar, Greenland), was an alleged Norse sorcerer who was burned in Greenland for sorcery and adultery.
In 1406, a Norwegian merchant ship arrived at the old Eastern Settlement on Greenland and stayed for four years. Among the passengers were the merchant Torgrim Sölvesson and his wife Steinunn Ravnsdotter. In 1407, Steinunn fell in love with Kolgrim and left Torgrim for him.
Torgrim accused Kolgrim of sorcery. The matter was raised at the Thing (tinget av lagmannen), which was conducted before the lagmannen and then tried before of a jury of twelve. At the witch trial at Gardar, witnesses were called, the Norwegian law against sorcery was invoked, and it was said that "Kolgrim brought [Steinunn] to him by use of magic" by reciting magic chants and galdr until she came to him and he "lay with her." The fact that Steinunn had fallen in love with Kolgrim was considered an even greater crime, since it meant that Kolgrim had "stolen" not only her body, but also her soul, from her husband. Kolgrim was found guilty of sorcery and condemned to death by burning at the place of execution at Gardar. After his execution, Steinunn was "never fully sane" again and died soon after.