Vikings: Valhalla season 2 also continued the story of Olaf Haraldsson, who at the end of season 1, was defeated by Forkbeard. Instead of killing him, Forkbeard made a deal with him in which Olaf would guide and protect Forkbeard’s grandson (and Canute’s son) Svein, who was appointed King of Norway, while Forkbeard protected Olaf’s son, Magnus.

https://screenrant.com/vikings-valhalla-season-2-ending-explained/