Bogdan Dimitrov Filov was a Bulgarian archaeologist, art historian and politician. He was prime minister of Bulgaria during World War II. During his tenure, Bulgaria became the seventh nation to join the Axis Powers.

The Tripartite Pact, also known as the Berlin Pact, was an agreement between Germany, Italy, and Japan signed in Berlin on 27 September 1940 by, respectively, Joachim von Ribbentrop, Galeazzo Ciano, and Saburō Kurusu and in the presence of Adolf Hitler. It was a defensive military alliance that was eventually joined by Hungary, Romania, Slovakia, Bulgaria, and Yugoslavia. Yugoslavia's accession provoked a coup d'état in Belgrade two days later. Germany, Italy, and Hungary responded by invading Yugoslavia. The resulting Italo-German client state, known as the Independent State of Croatia, joined the pact on 15 June 1941.