The Ustaše was a Croatian nationalist and fascist organization that emerged in the early 20th century. Founded in 1929, it aimed to create an independent Croatian state and was known for its extreme nationalist and anti-Serb ideology. The group gained power during World War II when it established the Independent State of Croatia in 1941, collaborating with the Axis Powers. During its rule, the Ustaše implemented policies of persecution and violence against ethnic Serbs, Jews, and Roma, leading to significant atrocities, including the establishment of concentration camps like Jasenovac. The regime was characterized by its brutal tactics and was ultimately dismantled after the war, with many members fleeing or facing justice for their actions.