日独伊三国同盟
On 25 March 1941, Prince Paul of Yugoslavia signed the Tripartite Pact, allying the Kingdom of Yugoslavia with the Axis powers. The Pact was extremely unpopular, particularly in Serbia and Montenegro, and demonstrations broke out. On 27 March, Serb military officers overthrew Prince Paul. The new government withdrew its support for the Axis, but did not repudiate the Tripartite Pact. Nevertheless, Axis forces, led by Nazi Germany invaded Yugoslavia in April 1941.