The Ustase (aka Ustasha) was an Croatian Fascist, Ultranationalist Terrorist Organization in Yugoslavia that was active between 1929 till 1945. They once ruled over Croatia under Their Leader Ante Pavelic after the Axis Invasion of The Kingdom of Yugoslavia. During WW2, They had been killing many Serbs, Jews and Romas and imprisoning them in concentration camps, most infamously Jasenovac where 700,000 prisoners were confirmed dead. The Organization had forced Serbs to convert to Catholicism and also be expelled. The Organization dissolved when the Axis were defeated in Europe and many members fled to Canada, Australia, Germany and some countries in South America, notably Argentina.