From Classic Encyclopedia 1911
ONNO KLOPP (1822-1903), German historian, was born at Leer on the 9th of October 1822, and was educated at the universities of Bonn, Berlin and Gottingen. For a few years he was a teacher at Leer and at Osnabruck; but in 1858 he settled at Hanover, where he became intimate with King George V., who made him his Archivrat. Thoroughly disliking Prussia, he was in hearty accord with George in resisting her aggressive policy; and after the annexation of Hanover in 1866 he accompanied the exiled king to Hietzing. He became a Roman Catholic in 1874. He died at Penzing, near Vienna, on the 9th of August 1903. Klopp is best known as the author of Der Fall des Hauses Stuart (Vienna, 1875-1888), the fullest existing account of the later Stuarts.
His Der König Friedrich II. and seine Politik (Schaffhausen, 1867) and Geschichte Ostfrieslands (Hanover, 1854-1858) show his dislike of Prussia. His other works include Der dreissigjahrige Krieg bis zum Tode Gustav Adolfs (Paderborn, 1891-1896); a revised edition of his Tilly im dreissigjdhrigen Kriege (Stuttgart, 1861); a life of George V., Kiinig Georg V. (Hanover, 1878); Phillipp Melanchthon (Berlin, 1897). He edited Corrispondenza epistolare tra Leopoldo I. imperatore ed it P. Marco l'Aviano capuccino (Gratz, 1888). Klopp also wrote much in defence of George V. and his claim to Hanover, including the Offizieller Bericht fiber die Kriegsereignisse zwischen Hannover and Preussen im Juni 1866 (Vienna, 1867), and he edited the works of Leibnitz in eleven volumes (1861-1884).
See W. Klopp, Onno Klopp: ein Lebenslauf (Wehberg, 1907).