Yugoslavia capitulates
Eleven days. The army had been mobilising when the attack came, was divided along national lines, and in Croatia substantial numbers of troops did not fight at all. The country was dismembered: parts to Germany, Italy, Hungary and Bulgaria, and a puppet Croatian state under the Ustaše whose campaign against Serbs, Jews and Roma began within weeks. The resistance and the civil war inside it ran for four years and are the reason Yugoslav casualty figures are so contested.