No ruler in modern times reigned in full sovereignty for as long as Francis Joseph, emperor of Austria and king of Hungary, Bohemia, Dalmatia, Croatia, and Slavonia. Titular master of central Europe from 1848 until 1916, he was center stage in Europe throughout the dramatic era in which Italy and Germany emerged as united nation states. His personal decisions were vital both to the outcome of the Crimean War and to the onset of World War I, sixty...