German Orientalist and explorer whose major work, Asia polyglotta nebst Sprachatlas (1823; “Asia Polyglotta with Language Atlas”), is one of the important early surveys of Oriental languages, notably the Caucasian languages, and is the only source of information on several extinct Caucasian languages.

Son of the chemist Martin Heinrich Klaproth, Heinrich won notice for accomplishments in language studies that brought him a teaching appointment at the St. Petersburg Academy. In 1805 he accompanied a Russian diplomatic mission to China and, following his return to St. Petersburg, made an extensive ethnographic and linguistic exploration of the Caucasus (1807–08), publishing Reise in den Kaukasus, 2 vol. (1814; “Travels in the Caucasus”). From 1815 he lived in Paris, becoming professor of Asiatic languages and literature in the pay of the king of Prussia in 1816. Much of what is known of the Indo-Iranian Ossetic language comes from Klaproth; his Asia polyglotta, though later superseded in certain respects, in its time formed a new departure for the classification of Eastern languages.