To ensure security to the southeast before invading Russia, Germany needed to occupy both Yugoslavia and Greece. A coup d’etat in Yugoslavia, revoking the terms of the Tripartite Pact between the Axis powers that granted German passage through Yugoslavia to Greece, had unsettled Hitler. Additionally, in October 1940, there had been a failed Italian counterattack on Greece after the Italians had invaded and been pushed back into Albania. Operation Marita – the simultaneous invasion of Yugoslavia and Greece – commenced on 6 April 1941. In Yugoslavia the Axis powers launched a German-led ground attack from Hungary, supported by units from Bulgaria in the south and Romania in the northeast. Blanket bombing over Belgrade on the first day killed 17,000 civilians, as well as destroying airfields. After just eleven days, Yugoslavia surrendered. Simultaneously, in Greece, the Germans easily overwhelmed the Greek army and Allied forces, forcing the Greeks to surrender and some 50,000 Allied troops to evacuate south to Crete, and some to Egypt.
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