The Flugumýrarbrenna (English: the Flugumýri Arson) was a quickfire that took place 22 October 1253 in Iceland during the Age of the Sturlungs.
[2] Gissur was at this time engaged in making amends and settling his quarrels with the Sturlungar clan.
On 22 October 1253, Eyjólfur ofsi Þorsteinsson and his followers put Flugumýri to the torch and clashed with Gissur and his men.
Eyjólfur was seeking vengeance for his expulsion from Skagafjörður and for the death of his father-in-law Sturla Sighvatsson who had died in the Battle of Örlygsstaðir at the hands of Gissur and his men.
25 people died in the ensuing fire and conflict, including Gissur's wife Gróa and their sons.