Gunnlaugur Guðbrandsson Briem was born at Brjánslækur in Barðastrandarýsla county, Iceland, on January 13, 1773. His parents were Guðbrandur Sigurðsson (1735–1779), a priest at Brjánslækur and his wife Sigríður Jónsdóttir (1747–1835). Briem’s father died of an accident while he was in his seventh year. A year later, he was fostered by the Reverend Björn Halldór Halldórsson in Sauðlauksdalur (1724–1794) and his wife Rannveig Ólafsdóttir from Svefneyjar (1734–1814). He grew up with them for the next eight years, most of the time at Setberg in Eyrarsveit. Briem sailed to Denmark at the age of 15 to study art and worked as a sculptor for a short time. There he met sculptor Bertel Thorvaldsen. After graduating from the Copenhagen Art Academy, Briem worked on his art for a while, but he also finished law studies in 1797. He went to Iceland in the summer of 1799 and became assistant to Jón Jakobsson, the county magistrate in Eyjafjörður (1738–1808). A year later he married Valgerður Árnadóttir (1779–1872). In the same year he was appointed to the Land property Committee, a task that included constant travel. Briem lived in various places for the next few years. For most of his life, Briem was engaged in governmental duties, but he was for the most part a magistrate at Grund in Eyjafjörður. However, he may be most known as one of the greatest patriarchs in Iceland in the later centuries.

The manuscript collection at the National and University Library preserves various manuscripts, letters, and official documents of Gunnlaugur Briem (Lbs 196-198 fol.)