Grégóríus Dagsson was a Norwegian district chieftain and a retainer of King Ingi Haraldsson. He was the son of Dagr Eilífsson and Ragnhildr, the daughter of Ǫgmundr Skoptason (see Genealogy XI in ÍF 28). In 1155 Grégóríus led the attack that caused the death of Ingi’s half-brother, Sigurðr munnr, in Bergen and he later joined Ingi in his fights against Sigurðr’s son, Hákon herðibreiðr. Grégóríus was killed by Hákon’s men at the battle of Fossum, near Uddevalla in present-day Sweden (on 7 January 1161), and he was buried at Gjerpen nunnery on Gimsøy, near Skien in Norway. For his life, see the references under Ingi Haraldsson above. See also Ágr (ÍF 29, 52-4; Ágr 1995, 78-81), Mork (Mork 1928-32, 448-53; Andersson and Gade 2000, 394-8).
Events documented in poetry: The slaying of Sigurðr munnr in 1155 (ESk Ingdr 2-4); the battle of the Götaälv in 1159 (ESk Elf).