Ukrainian Insurgent Army

The Ukrainian Insurgent Army (Ukrainian: Українська Повстанська Армія (УПА), "Ukrayins’ka Povstans’ka Armiya", orUPA) was a large and well organized Ukrainian nationalist military and later partisan army that engaged in a series of guerrilla conflicts during World War II against Nazi Germany, the Soviet Union, Czechoslovakia, and both Underground and Communist Poland. The group was the military wing of the Organization of Ukrainian Nationalists — Bandera faction (the OUN-B), originally formed in Volyn (northwestern Ukraine) in the spring and summer of 1943. Its official date of creation is October 14.

The OUN's stated immediate goal was the establishment of a united, independent national state on Ukrainian ethnic territory. Violence was accepted as a political tool against foreign as well as domestic enemies of their cause, which was to be achieved by a national revolution led by a dictatorship that would drive out the occupying powers and set up a government representing all regions and social groups. The organization began as a resistance group and developed into a guerrilla army.

During its existence, the Ukrainian Insurgent Army fought against the Poles and the Soviets as their primary opponents, although the organization also fought against the Germans starting from February 1943. From late spring 1944, the UPA and Organization of Ukrainian Nationalists-B (OUN-B) — faced with Soviet advances — also temporarily cooperated with German forces against the Soviets and Poles in the hope of creating an independent Ukrainian state. The army also played a substantial role in ethnic cleansing of the Polish population of Volhynia and East Galicia, as well as subsequent defending the Ukrainian population and preventing deportation of the Ukrainians in South-Eastern Poland.

After the end of the World War II, the Polish communist army — the People's Army of Poland — fought extensively against the UPA. The UPA remained active and fought against the People's Republic of Poland until 1947, and against the Soviet Union until 1949. It was particularly strong in the Carpathian Mountains; the entirety of Galicia and in Volyn — in modern Western Ukraine. Among the anti-Nazi resistance movements, it was unique in that it had no significant foreign support. Its growth and strength were a reflection of the popularity it enjoyed among the people of Western Ukraine. Outside of Western Ukraine, support was minimal, and the majority of the Soviet (eastern) Ukrainian population considered the OUN/UPA to have been primarily collaborators with the Germans.

The UPA was formally disbanded in early September, 1949. However, some of its units continued operations until 1956.

Another separate, independent UPA also existed in Volyn from 1941 until July 1943. It was nominally formed earlier in late November 1941, and from the spring of 1942 was a most active Ukrainian nationalist armed group before the formal formation of the UPA in the spring of 1943. This group belonged to political opponents of the OUN(B) - OUN(UNR), and allied itself politically with OUN(M). This grouping led by Taras Bulba-Borovets had links to the Ukrainian National Republic (UNR) in exile. It was renamed the Ukrainian People's Revolutionary Army in July 1943 before being later partially and forcibly absorbed into the UPA of the OUN(B).