Anti-Fascist Struggle Day () is a legally mandated public holiday in Croatia. It is observed on 22 June and commemorates the formation of the First Sisak Partisan Detachment (a Communist-led guerrilla unit) in the Axis-allied Independent State of Croatia on 22 June 1941. On that day, Germany attacked the Soviet Union and the Communist Party of Yugoslavia (CPY) received orders from the Moscow-based Comintern to come to the Soviet Union′s aid. Prior to that, although Yugoslavia had been routed and occupied by Germany and Italy in mid-April 1941, the CPY had not rendered active resistance until ordered to do so by Moscow, as Nazi Germany and Soviet Russia had adhered to the non-aggression pact the parties had signed in August 1939.