LEO, HEINRICH (1799-1878), German historian, was born at Rudolstadt on March 19, 1799, his father being chaplain to the garrison there. As a student (1816-2o) at the universities of Breslau, Jena and GOttingen, Leo fell under radical influences and at Jena he attached himself to the radical wing of the Ger man Burschenschaft, the so-called "Black Band," under the leader ship of Karl Follen. The murder of Kotzebue by Karl Sand, however, shocked him out of his extreme revolutionary views, and from this time he tended, under the influence of the writings of Hamann and Herder, more and more in the direction of con servatism and romanticism, until at last he became an extreme reactionary. He was Privatdocent at Erlangen, Docent (1822-27) at Berlin and for nearly 4o years (183o-68) professor at Halle.
inclination towards Catholicism; and Leo did actually glorify the counter-Reformation, e.g., in his Zwolf Bucher niederldndischer Geschichte ( 2 vols., 1832-35). His other historical works, and particularly his Universalgeschichte (6 vols., 1835-44) are biassed by his reactionary views.
Leo was by nature highly excitable and almost insanely pas sionate, though at the same time strictly honourable, unselfish, and in private intercourse even gentle. During the last year of his life his mind suffered rapid decay, of which signs had been apparent as early as 1868. He died at Halle on April 24, 1878. He left an account of his early life (Meine Jugendzeit, Gotha, 188o), which is of interest.