A partisan is a member of an irregular military force formed to oppose control of an area by a foreign power or by an army of occupation by some kind of insurgent activity. The term can apply to the field element of resistance movements, examples of which are the civilians that opposed Nazi German or Fascist Italian rule in several countries during World War II.
The French term "partisan", derived from the Latin, first appeared in the 17th century to describe the leader of a war-party.
The initial concept of partisan warfare involved the use of troops raised from the local population in a war zone (or in some cases regular forces) who would operate behind enemy lines to disrupt communications, seize posts or villages as forward-operating bases, ambush convoys, impose war taxes or contributions, raid logistical stockpiles, and compel enemy forces to disperse and protect their base of operations.
One of the first manuals of partisan tactics in the 18th century was The Partisan, or the Art of Making War in Detachment..., published in London in 1760 by de Jeney, a Hungarian military officer who served in the Prussian Army as captain of military engineers during the Seven Years' War of 1756–1763. Johann von Ewald described techniques of partisan warfare in detail in his Abhandlung über den kleinen Krieg (1789).
The concept of partisan warfare would later form the basis of the "Partisan Rangers" of the American Civil War. In that war, Confederate States Army Partisan leaders, such as John S. Mosby, operated along the lines described by von Ewald (and later by both Jomini and Clausewitz). In essence, 19th-century American partisans were closer to commando or ranger forces raised during World War II than to the "partisan" forces operating in occupied Europe. Mosby-style fighters would have been legally considered uniformed members of their state's armed forces.
Partisans in the mid-19th century were substantially different from raiding cavalry, or from unorganized/semi-organized guerrilla forces. Russian partisans played a crucial part in the downfall of Napoleon. Their fierce resistance and persistent inroads helped compel the French emperor to flee Russia in 1812.
Imperial Russia also made use of partisans in World War I, for example Stanisław Bułak-Bałachowicz.
The Ukrainian Insurgent Army (Ukrainian: Українська Повстанська Армія (УПА), Ukrayins’ka Povstans’ka Armiya; UPA) was a Ukrainian nationalist paramilitary 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 in the spring and summer of 1943. Its official date of creation is 14 October 1942, day of Intercession of the Theotokos feast.
The OUN's stated immediate goal was the re-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 cooperated with German forces against the Soviets and Poles in the hope of creating an independent Ukrainian state. The army also perpetrated ethnic cleansing of the Polish population of Volhynia and East Galicia, as well as subsequently defending the Ukrainian population in Poland from deportations; preventing the deportation of the Ukrainians in southeastern Poland.
Soviet partisans during World War II, especially those active in Belarus, effectively harassed German troops and significantly hampered their operations in the region. As a result, Soviet authority was re-established deep inside the German-held territories. In some areas partisan kolkhozes raised crops and livestock to produce food. However this was not usually the case and partisans also requisitioned supplies from the local populace, sometimes involuntarily.
Soviet partisans in Finland were known to have attacked villages and indiscriminately target the populace, killing entire families. The war crimes committed in Finland by Soviet partisans were investigated by the National Bureau since 1999. However, Russia refused access to Soviet archives and the investigation ended in 2003. Partisan warfare was routinely distorted in the Soviet Union. According to historian Veikko Erkkilä the Russian attitude towards civilian atrocities has been marred by the Great Patriotic War propaganda. In East Karelia, most partisans attacked Finnish military supply and communication targets, but inside Finland proper, almost two-thirds of the attacks targeted civilians, killing 200 and injuring 50, mostly women, children and elderly.
The Yugoslav Partisans or the National Liberation Army (officially the National Liberation Army and Partisan Detachments of Yugoslavia), was Europe's most effective anti-Nazi resistance movement. It was led by the Communist Party of Yugoslavia during World War II. Its commander was Marshal Josip Broz Tito. They were a leading force in the liberation of their country during the People's Liberation War of Yugoslavia.
By the middle of 1943 partisan resistance to the Germans and their allies had grown from the dimensions of a mere nuisance to those of a major factor in the general situation. In many parts of occupied Europe the enemy was suffering losses at the hands of partisans that he could ill afford. Nowhere were these losses heavier than in Yugoslavia.
By late 1944, the total forces of the Partisans numbered 650,000 men and women organized in four field armies and 52 divisions, which engaged in conventional warfare. By April 1945, the Partisans numbered over 800,000.
Shortly before the end of the war, in March 1945, all resistance forces were reorganized into the regular armed force of Yugoslavia and renamed Yugoslav Army. It would keep this name until 1951, when it was renamed Yugoslav People's Army.
Postwar Yugoslavia was one of only two European countries that were largely liberated by its own forces during World War II. It received significant assistance from the Soviet Union during the liberation of Serbia, and substantial assistance from the Balkan Air Force from mid-1944, but only limited assistance, mainly from the British, prior to 1944. At the end of the war no foreign troops were stationed on its soil. Partly as a result, the country found itself halfway between the two camps at the onset of the Cold War.