Franz Jo·sef I 
(frănz jōzəf, -səf, frănts, fränts yōzĕf) also Francis Joseph I 1830-1916.
(frănz jōzəf, -səf, frănts, fränts yōzĕf) also Francis Joseph I 1830-1916. Emperor of Austria (1848-1916) and king of Hungary (1867-1916) who divided (1867) his empire into a dual monarchy, Austria-Hungary. His ultimatum to Serbia after the 1914 assassination of his nephew Franz Ferdinand led to World War I.