Ukrainian Insurgent Army
The Ukrainian Insurgent Army (Ukrainian: Українська повстанська армія, УПА, romanized: Ukrainska Povstanska Armiia, abbreviated UPA) was a Ukrainian nationalist partisan formation founded by the Banderite faction of the Organisation of Ukrainian Nationalists (OUN) on 14 October 1942, existing until the 1950s. The UPA launched guerrilla warfare against the Soviet Union, the Polish people (both the Polish Underground State resistance and Soviet-backed forces as well as against civilians), and against Nazi Germany, though in so doing initially motivated by anti-German ethnic exclusionary sentiment, and ultimately entering collaboration with the Germans on common totalitarian ideological grounds by late 1944.