 Brønlund, an Inuit and the son of a hunter, was born in Ilulissat, Greenland, then known as Jakobshavn, on 14 December 1877.He was a childhood friend of Knud Rasmussen whose father was a priest in Jakobshavn.Trained as a teacher, Brønlund graduated in 1901 from Nuuk College and was employed as a catechist at a trading post near the Nuup Kangerlua estuary.