Sörla þáttr eða Heðins saga ok Högna is a short narrative from the extended version Óláfs saga Tryggvasonar en mesta found in the Flateyjarbók manuscript, which was written and compiled by two Christian priests, Jon Thordson and Magnus Thorhalson, in the late 14th century. The narrative begins 24 years after the death of Fróði, and takes place in the 9th and the 10th centuries. It is a composite tale containing a story of how Freyja acquired a necklace from the Dwarves, how that led to a bloody war, and how Olaf Tryggvason brought peace to the land.

Flateyjarbók is an important medieval Icelandic manuscript. It is also known as GkS 1005 fol. and by the Latin name Codex Flateyensis. It was commissioned by Jón Hákonarson and produced by the priests and scribes Jón Þórðarson and Magnús Þórhallsson.