The Battle of Fýrisvellir was a battle for the throne of Sweden which was fought in the 980s on the plain called Fýrisvellir, where modern Uppsala is situated, by King Eric the Victorious and his nephew Styrbjörn the Strong. It is mentioned in a number of medieval sources, such as Eyrbyggja saga, Knýtlinga saga, Hervarar saga and Saxo Grammaticus' Gesta Danorum (Book 10), but the most detailed account is found in the short story Styrbjarnar þáttr Svíakappa.