Axis leaders Adolf Hitler and Italian prime minister Benito Mussolini meet in Munich, Germany, 1940. Photograph »

Slovak prime minister Vojtech Tuka (front row, standing) announces Slovakia's entry into the Axis alliance (initially Germany, Italy, and Japan; also joined by Hungary, Romania, and Bulgaria). Berlin, Germany, November 1940. Photograph »

Bulgarian leader Bogdan Filov (standing) and German foreign minister Joachim von Ribbentrop (seated, center) during the signing of the Tripartite Pact. This treaty formally aligned Bulgaria with the Axis powers. Vienna, Austria, March 1, 1941. Photograph »