M0498900 (mo͞o′sə-lē′nē, mo͝os′ə-, mo͞os′sō-), Benito Amilcare Andrea Known as "Il Duce." 1883-1945. Italian Fascist dictator and prime minister (1922-1943) who conducted an expansionist foreign policy, formalized an alliance with Germany (1939), and brought Italy into World War II (1940). Dismissed by Victor Emmanuel III (1943), he led a puppet Nazi government in northern Italy until 1945, when he was assassinated.