He was born at Copenhagen, and studied at the university there, passing his theological examination in 1791. After spending some time in the German universities, he visited France and England. Returning to Denmark, he wrote numerous works; was appointed professor of theology at the University of Copenhagen in 1801, and in 1830 became Bishop of Zealand, the highest ecclesiastical dignity in Denmark.
He was an eminent theologian, and his theological works, including that on the Christian moral system (1808) and other volumes, are very highly valued. But his literary reputation rests upon his essays on Danish and Norse antiquities, of which the most valuable are: Om det islandske Sprogs Vigtighed (1813), Kritisk Undersögelse af Danmarks og Norges Sagnhistorie (1823–30), and, above all, his “Library of the Sagas” (Danish: Sagabibliothek, 1810–18). From 1805 to 1832, he was editor of the “Danish Literary Gazette” (Danish: Dansk Literatur Tidende).