In 1939, Italy occupied Albania, and in 1940 invaded Greece. The Italians were driven back into Albania, however, and Greek forces again took control of northern Epirus. The conflict marked the first tactical victory of the Allies in World War II. Benito Mussolini himself supervised the massive counter-attack of his divisions in spring 1941, only to be decisively defeated again by the poorly equipped, but determined, Greeks. Nazi Germany then intervened in April 1941 to avert an embarrassing, wholesale Italian defeat. The German military performed rapid military maneuvers through Yugoslavia and forced the encircled Greek forces of the Epirus front to surrender.