Organisation of Ukrainian Nationalists

The Organisation of Ukrainian Nationalists (OUN; Ukrainian: Організація українських націоналістів, romanized: Orhanizatsiia ukrainskykh natsionalistiv) was a Ukrainian nationalist organization established on February 2, 1929 in Vienna, uniting the Ukrainian Military Organization with smaller, mainly youth, radical nationalist right-wing groups. The OUN was the largest and one of the most important far-right Ukrainian organizations operating in the interwar period on the territory of the Second Polish Republic.

Source: Wikipedia — Organisation of Ukrainian Nationalists (CC BY-SA 4.0)