Balkans Campaign
Although minister president, Pál Teleki, had signed a friendship and non-aggression treaty with Yugoslavia in December 1940, in March 1941 Hungary allowed the German "Wehrmacht" to march through Hungarian territory. On 11 April 1941, following Telekis' suicide and by Hitler's invitation, the Hungarian 3rd Army joined the Balkans Campaign in the wake of which Bačka, Baranya, Prekmurje and Medjimurje were annexed.