On this day in 1941, the German and Italian invaders of Yugoslavia set up the Independent State of Croatia (also including Bosnia and Herzegovina) and place nationalist leader Ante Pavelic's Ustase, pro-fascist insurgents, in control of what is no more than a puppet Axis regime.
The Ustase began a relentless persecution of Serbs, Jews, Gypsies, and antifascist Croats. As many as 350,000 to 450,000 victims were massacred, and the Jasenovac concentration camp would become infamous as a slaughterhouse.
Croatia's Serbs gave sporadic resistance, but it was the communist partisans, led by Josip Broz Tito (a Croat himself), who provided antifascist leadership. By 1944, most of Croatia--apart from the main cities--was liberated from Axis forces, and Croats joined partisan ranks in large numbers. As the war neared its end, however, many Croats, especially those who had been involved with the Ustase regime or who had opposed the communists, sought refugee status with the Allies. But British commanders handed them over to the partisans, who slaughtered tens of thousands, including civilians, on forced marches and in death camps.