A partisan (; ; also partizan) is a member of a domestic irregular military force formed to oppose control of an area by a foreign power or by an army of occupation through some form of insurgent activity.

The term can apply to the field element of resistance movements. The most common use in present parlance in several languages refers to occupation resistance fighters during World War II, especially under the Yugoslav partisan leader Josip Broz Tito.

History before 1939

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.

George Satterfield has analyzed the "partisan warfare" () in the Netherlands campaigns of 1673–1678 during the Franco-Dutch War of 1672–1678. Some of the practices of ninjas in feudal Japan resembled irregular partisan warfare.

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, produced one of the first manuals of partisan tactics in the 18th century: The Partisan, or the Art of Making War in Detachment... (English translation published in London in 1760.)de Jeney, L. M. [Lewis Michael]: The Partisan, or the Art of Making War in Detachment..."translated from the French of Mr. de Jeney, by an Officer of the Army" [Thomas Ellis]. London: 1760. from French edition in Hag, 1757 see Mihály Lajos Jeney Johann von Ewald described techniques of partisan warfare in detail in his Abhandlung über den kleinen Krieg ("Treatise on little war", Cramer: Cassel, 1785).Abhandlung über den kleinen KriegEwald J. (ed. & trans. Selig, R. and Skaggs, D) "Treatise on Partisan Warfare", Greenwood Press (1991)

The concept of partisan warfare would later form the basis of the "Partisan Rangers" of the American Civil War of 1861–1865. In that war, Confederate States Army Partisan leaders, such as John S. Mosby, Jesse James, William Quantrill, and Bloody Bill Anderson, operated along the lines described by von Ewald (and later by both Jomini (1779–1869) and Clausewitz (1780–1831)). In essence, 19th-century American partisans were closer to commando or ranger forces raised during World War II than to the partisan forces which would operate in Nazi-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 retreat from Russia after invading in 1812 (e.g., the activities of Denis Davydov). The Boers also deployed the concept of partisan warfare with their kommandos during the Second Boer War of 1899–1902.

Imperial Russia also made use of partisans in World War I, for example Stanisław Bułak-Bałachowicz.

By region French

French resistance during World War II arose after the armistice in June 1940 and the creation of the collaborationist Vichy regime. Charles de Gaulle, military leader exiled in London, led the Free French Army. It fought alongside the Allies and rallied the various French overseas colonies to fight back against the Vichy régime and the Axis forces in Africa and the Pacific.

Meanwhile, various resistance groups were created by working class men refusing to be drafted for forced labour in Germany. Fleeing into forests and mountains, they created maquis, which became increasingly more organized and armed as the war went on. They had an estimated to members in autumn of 1943 and approximately members in June 1944.

Communist resistance started actively organizing after the invasion of the Soviet Union in June 1941. Their armed movement was the Francs-Tireurs et Partisans (FTP). By 1944, the FTP had an estimated strength of 100,000 men. Some killed high-ranking German officers, but these assassination were soon abandoned after the German execution of dozens of hostages in retaliation. They conducted sabotage (mostly train derailing) and guerilla warfare.

In 1943, de Gaulle sent Jean Moulin to unite the various resistance groups under one single organization, the National Council of the Resistance.

In 1944, the French Forces of the Interior (FFI) numbered more than 100,000 men and played a great role in helping the allied forces succeed at the Normandy landings and the Battle of Normandy. Free French forces (both interior resistance and the French Liberation Army) successfully liberated Paris in August 1944.

French partisans were also joined by resistance fighters of other nationalities, such as Armenians (Manouchian group), Poles or Spanish republicans in exile.

Greek

The Greek resistance during World War II arose in response to the triple occupation of Greece by Nazi Germany, Fascist Italy, and Bulgaria from April 1941 to October 1944. Germany controlled strategic areas like Athens and Crete, Italy held most of the mainland and islands until its surrender in September 1943, and Bulgaria annexed parts of Macedonia and Western Thrace. As early as the Battle of Crete in the last third of May 1941, German paratroops encountered mass resistance from the civilian population. Among the earliest acts of defiance, on May 30, 1941, students Manolis Glezos and Apostolos Santas tore down the Nazi swastika from the Acropolis. In June 1941, soon after the fall of Crete, the Supreme Committee of Cretan Struggle (AEAK) was formed. It was the first armed resistance organization, launching intelligence gathering and organizing the evacuation of stranded Allied soldiers to Egypt.

The occupation's hardships, including the Great Famine of 1941–42, which claimed the lives of approximately 300,000 civilians, fueled resistance. Resistance groups, known as andartes, created "Free Greece" by mid-1943, controlling roughly 30,000 km² with 750,000 inhabitants. To counter resistance, harsh reprisals against civilians were extensively inflicted. Entire villages were burned and mass executions carried out, such as the massacres of Kandanos (June 1941, ~180 killed), Kommeno (August 1943, ~320 killed), Viannos (September 1943, ~500 killed), Kalavryta (December 1943, ~500 killed), Distomo (June 1944, ~218 killed), and the shootings of Kaisariani (May 1944, 200 killed). Such collective punishment targeting civilians in response to partisan actions left nearly 1 million homeless and 50,000–70,000 executed overall.

The largest resistance groups were the communist-led National Liberation Front (EAM) and its military arm, the Greek People's Liberation Army (ELAS), with over 50,000 members by 1944, led by Aris Velouchiotis, Samariniotis and Sarafis, and the republican, anti-communist National Republican Greek League (EDES), led by Napoleon Zervas with ~12,000 fighters. EAM/ELAS dominated rural areas, conducting sabotage and guerrilla warfare, while EDES was active in northern Greece. Smaller organizations such as PEAN were active in cities. PEAN's most spectacular act was the bombing of the collaborationist ESPO's headquarters in 1942, who was trying to recruit volunteers for a "Greek Legion" to fight in the Eastern Front alongside Germans. A rare joint operation occurred in November 1942, when ELAS, EDES, and British SOE agents destroyed the Gorgopotamos viaduct in Operation Harling, disrupting Axis supply lines. However, ideological tensions led to ELAS attacking groups like EKKA and clashing with EDES in 1943–44, amid fears of a communist post-war takeover. These conflicts, alongside battles against collaborationist Security Battalions, foreshadowed the Greek Civil War. After the German withdrawal in October 1944, EAM/ELAS's attempt to seize control clashed with British-backed EDES and government forces. This erupted into the Dekemvriana (December 1944–January 1945), a 37-day conflict in Athens where ELAS fought British troops and anti-communist factions, resulting in thousands of deaths and marking the first phase of the Greek civil war, driven by Cold War rivalries and internal divisions.

Hungarian Hundreds of Hungarians fought in the Slovak National Uprising notably in the Nógrádi and Petőfi groups (after Petőfi Sándor, Hungarian poet from the Hungarian War of Independence). They also appeared in significant numbers in 20 other units, but unfortunately this did not have an effect on the Kassa declaration (Kassai nyilatkozat). Many activists fought abroad like Kilián György activist and soldier in Poland or Szalvai Mihály politician, who fought in Moscow and Yugoslavia. Many have been martyrs in the French Resistance like Elek Tamás and Botzor József. The Sovereignty movement took over multiple newspapers including the Népszava, the Magyar Nemzet, and the Szabad Szó, to propagate anti-fascist and anti-german sentiment. Their main goal being to break away from the Axis powers. Most of these groups were decentralised, multiple paramilitary groups worked in Budapest in parallel. The most famous of which operated in Angyalföld, under Gidófalvy Lajos, who died a heroic death while trying to prevent the blowing up of the Elizabeth Bridge. They forged papers, protected the Ferdinánd-bridge, took over vehicles, weapons and multiple factories.

Italian

On 28 October 1922, Benito Mussolini and his fascist paramilitary troops, the Blackshirts, marched on Rome, seized power, and the following day Mussolini became Duce (Prime Minister) of Italy. He thenceforth established a dictatorship centered around his fascist doctrine, and in 1936 Mussolini formed the Axis powers with Nazi Germany. In July 1943, fascist Italy crumbled; Mussolini was turned in by the monarchy and placed under arrest by his government.

On 8 September 1943, when the armistice of Cassibile was announced, Germans invaded Italy and liberated Mussolini, putting him in charge of the Italian Social Republic, a collaborationist regime and puppet state of the Third Reich. Subsequently, the Italian resistance movement, alongside the Italian Co-Belligerent Army, fought the German and Fascist forces.

One of the most important episodes of resistance by Italian armed forces after the armistice was the battle of Piombino, Tuscany. On 10 September 1943, during Operation Achse, a small German flotilla, commanded by Kapitänleutnant Karl-Wolf Albrand, tried to enter the harbor of Piombino but was denied access by the port authorities.

Eventually, after a drawn-out period of combat, the Italian partisans achieved victory. This was assisted by the fall of the Third Reich, which effectively nullified the attacks from German occupation, the ensuing uprising of 25 April 1945 which pushed out all remaining German forces, the fall of Genoa and Milan on April 26, that of Turin two days after. That same day, Mussolini was captured; he was executed on April 28 by Italian partisan Walter Audisio. German forces in Italy officially surrendered on May 2.

Lithuanian