Born Mar. 15, 1794, in Giessen; died May 29, 1876, in Bonn. German philologist of Romance languages; founder of the comparative study of the Romance languages; professor at the University of Bonn beginning in 1823. Diez’ major works were a grammar and an etymological dictionary of the Romance languages. He is also well known for his research in Old Provencal literature and the poetry of the troubadours.