Haase, Hugo (
hū'gō hä'zə) , 1863–1919, German Socialist leader. A Social Democratic member of the Reichstag, he opposed World War I, but initially followed his party's position in supporting the war. In Dec., 1915, he split with the Social Democrats under Friedrich
Ebert, who replaced him as leader in the Reichstag. In 1917, Haase and his followers formed the Independent Social Democratic party. After the proclamation of a German republic in Nov., 1918, Haase joined with Ebert and Philipp
Scheidemann in forming the new government, but his party was unwilling to accept the “bourgeois revolution” of the Social Democrats and withdrew late in December. Haase was murdered by a personal enemy.