A Bohemian church reformer; was a disciple of Wyclif, and did much to propagate his teaching, in consequence of which he was summoned in 1414 to answer for himself before the Council of Constance; went under safe-con duct from the emperor; "they laid him instantly in a stone dungeon, three feet wide, six feet high, seven feet long; burnt the true voice of him out of this world; choked it in smoke and fire" (1373-1415).