A variety of partisan groups sprang up, the largest being the Ukrainian Insurgent Army or UPA, controlled by the Banderivtsi. Fielding up to 200,000 men, for a few months in the autumn and winter of 1943 it controlled most of north-west Ukraine, establishing a primitive administration and its own training camps and hospitals. Even more remarkably, small UPA guerrilla units carried on an assassination and sabotage campaign against the Soviet Union for years after the end of the war.
