German trains rolled through the mountains of Yugoslavia under constant threat from partisan sabotage. To understand those partisan attacks, first picture the Balkans before the war. The region was politically fragile, ethnically mixed, and economically uneven. Two states mattered most for our story. One was the Kingdom of Yugoslavia. The other was the Kingdom of Greece. Both contained sharp social conflicts, nationalist tensions, and weak democratic traditions. These prewar conditions shaped how resistance and collaboration would unfold during occupation. Yugoslavia was created after the First World War as a South Slav kingdom. It brought together Serbs, Croats, Slovenes, Montenegrins, and others under one monarchy. Serb political elites dominated the central institutions. Many Croats and Slovenes resented that dominance. Macedonians and Bosnian Muslims had complex and contested identities. The state also faced strong communist organizing, especially among workers and students. By the late nineteen thirties the king ruled through an authoritarian royal dictatorship. Political life was bitterly polarized when the Second World War erupted. Greece was a smaller country but equally unstable. It had endured the catastrophic population exchange with Turkey. It wrestled with refugee integration and economic crises. Greek politics swung between parliamentary experiments, coups, and royal interventions. The communist party had been harshly repressed under the Metaxas dictatorship. The army contained both monarchist and republican networks. Like Yugoslavia, Greece entered the war with deep internal fractures that occupation would widen. Axis powers invaded Yugoslavia and Greece in April nineteen forty one. The campaigns were swift and devastating. Germany attacked to secure its southern flank before turning against the Soviet Union. Italy sought prestige and influence in the region. Bulgaria and Hungary aimed to revise borders from the previous settlement. After brief resistance, both Yugoslavia and Greece collapsed militarily. Their governments fled. Their territories were carved into occupation zones and satellite states. Yugoslavia was dismembered in particularly complex ways. Germany held key industrial and transport areas in Serbia and Slovenia. Italy controlled large coastal zones and inland regions. Hungary and Bulgaria annexed border territories with substantial minorities. The Independent State of Croatia was proclaimed under fascist Ustaša leadership. This new state included most of Croatia and Bosnia. It combined radical Croatian nationalism with genocidal policies. Serbs, Jews, and Roma faced forced conversions, expulsions, and mass killings. This brutality would fuel both resistance and retaliatory massacres.

Greece also experienced fragmented occupation. Germany controlled strategic regions. These included Athens, Salonika, and many islands. Italy administered much of the countryside and more islands. Bulgaria occupied northeastern territories with a significant Slavic speaking population. Greek Jews, especially those in Salonika, faced rapid persecution and eventual deportation. Economic exploitation, requisitions, and shipping losses created severe food shortages. The winter of nineteen forty one and nineteen forty two brought famine, especially in urban centers. Occupation policies were harsh across the region but varied by zone. German authorities prioritized security and resource extraction. They used collective reprisals against civilians for attacks on their forces. Italian commanders often used negotiation and local alliances, but could also be brutal. Their weakness sometimes allowed resistance to grow in the Italian zones. Bulgarian and Hungarian forces pursued their own national agendas. They encouraged friendly national identities and repressed others. All these policies transformed everyday survival into a political question. In this environment different resistance movements emerged. They were not simply patriotic guerrillas. They reflected ideological divides, national projects, and social conflicts. In Yugoslavia the two main resistance movements were the communist led partisans and the monarchist Chetniks. In Greece, communist and non communist resistance developed in rivalry and occasional cooperation. Understanding these movements requires following their origins first, then their wartime evolution. The Yugoslav communists had been illegal since the interwar years. They maintained a disciplined underground network despite repression. Their leader, Josip Broz Tito, had survived arrests, prison, and exile. The party had strong ties to the Soviet Union but also localized strategies. When Germany invaded the Soviet Union in June nineteen forty one, communist parties across Europe received a new directive. They were to shift from caution to active armed resistance. In Yugoslavia this moment transformed the party from a clandestine group into a mass partisan movement. Tito and his comrades began forming armed detachments in Serbia and elsewhere. They drew volunteers from workers, students, and radicalized peasants. The first attacks targeted gendarmerie posts, rail lines, and supply depots. The communists framed the struggle as both national liberation and social revolution. They called for unity of all Yugoslav peoples against occupiers and collaborators. This universal appeal contrasted with nationalist projects that privileged one group. It made the partisans attractive for many marginalized communities. At the same time a different resistance emerged from the royalist military tradition. In Serbia Colonel Draža Mihailović gathered scattered officers and soldiers. They called themselves Chetniks, recalling earlier guerrilla fighters against the Ottomans. Their declared goal was restoration of the Yugoslav monarchy and preservation of Serb interests. Initially they engaged in limited attacks against occupiers. However they feared brutal German reprisals against Serbian civilians. They also feared the communist agenda among the partisans. These concerns pushed them toward caution and eventually toward selective collaboration. The conflict between partisans and Chetniks deepened rapidly. The partisans insisted on continuous offensive action. They argued that occupation brutality would continue regardless of resistance. For them armed struggle itself would mobilize the population and undermine collaborators. The Chetnik leadership preferred to conserve forces for a later uprising. They expected a landing of British forces in the Balkans. They hoped to emerge then as the recognized national army. The British initially supported Mihailović. They sent missions and supplied weapons. Yet British officers also observed growing Chetnik passivity and local deals with Axis authorities. Partisan strategy emphasized mobility and political work. Small units operated in rugged terrain, attacking isolated posts and supply lines. After each action they held political meetings with villagers. They distributed leaflets explaining their goals. They set up local committees that included different nationalities and faiths. These committees handled food distribution, security, and rudimentary justice. The movement presented itself as the embryo of a new Yugoslavia. This approach gained traction in ethnically mixed areas like Bosnia and Croatia, where previous regimes had favored one group. Chetnik forces organized differently. Their core lay in Serb populated highland regions of Serbia, Bosnia, and Montenegro. Many of their commanders were prewar officers or local notables. They often viewed Croats and Muslims with suspicion or hostility. In mixed regions some Chetnik units committed massacres and expulsions against non Serb civilians. They justified these actions as preemptive or retaliatory measures. Such policies undermined claims to represent a united Yugoslavia. They also pushed many threatened communities toward the partisans despite communist ideology. German and Italian forces exploited these divisions. When facing strong partisan pressure, occupation authorities sometimes armed Chetnik units as auxiliaries. They used them for anti guerrilla sweeps or for guarding key lines. In return, Chetnik leaders hoped to secure local authority and delay confrontation with Axis forces. This collaboration was often tactical and localized. Yet over time it created a cumulative pattern. British intelligence traffic, captured documents, and field reports convinced London that Mihailović was no longer a reliable main partner. Meanwhile the partisans survived a series of major Axis offensives. Between late nineteen forty one and nineteen forty three German, Italian, Croatian, and other forces launched repeated encirclement operations. They used large troop concentrations and aircraft to crush partisan strongholds. The partisans responded with flexible retreats, sudden counterattacks, and painstaking reorganization. They suffered very high casualties but maintained their core units. Each survival enhanced their prestige among the population and in Allied eyes. By nineteen forty three they controlled sizable liberated territories, especially in Bosnia and western Yugoslavia. The movement’s political dimension grew alongside its military expansion. Tito’s leadership proclaimed the Anti Fascist Council of National Liberation of Yugoslavia. This body functioned as a provisional parliament. It brought delegates from all Yugoslav peoples into its sessions. Its resolutions promised equality of nations, women’s suffrage, and agrarian reform. The council also declared itself the supreme authority of future Yugoslavia. This claim directly challenged both occupation regimes and the government in exile. The Allies closely watched this evolution. British and American missions were inserted into both Chetnik and partisan headquarters. Their reports emphasized operational effectiveness. They documented who actually attacked German transport and disrupted supply. By late nineteen forty three the assessment was clear. The partisans were tying down significant Axis forces. The Chetniks were often avoiding combat and occasionally cooperating with occupiers. As a result the Allies shifted material and diplomatic support decisively toward Tito. A similar but distinct story unfolded in occupied Greece. The most influential resistance movement there was the National Liberation Front, known by its Greek initials. It formed in late nineteen forty one under communist initiative but included other left leaning groups. Its military wing was the Greek People’s Liberation Army. Like the Yugoslav partisans, it framed the struggle as both national and social. It recruited heavily from rural poor, urban workers, and persecuted activists. Its fighters operated mainly in mountainous regions, harassing Italian and German forces.

The Greek communists had learned from repression during the Metaxas dictatorship. They focused on broad alliances rather than narrow party control. Within the Liberation Front, communists worked with agrarian, socialist, and republican partners. They organized not only guerrilla detachments but also neighborhood committees and cultural groups. In many villages the movement became the primary authority. It managed food supplies, justice, and education under occupation conditions. This created a powerful legitimacy that weakened collaborationist governments in Athens. Non communist resistance also developed in Greece. The National Republican Greek League formed around officers with Venizelist republican backgrounds. Its leader, Napoleon Zervas, established units mainly in Epirus. This movement had a more traditional military outlook and skeptical views of communists. It cooperated with British intelligence and Special Operations Executive missions. There were also smaller royalist and nationalist groups, including urban cells focused on intelligence gathering and sabotage. The Greek resistance scene therefore mirrored Yugoslavia in its plurality and rivalries. One dramatic success of Greek resistance cooperation became famous among Allied planners. In November nineteen forty two a joint team from the Liberation Army and the Republican League, assisted by British saboteurs, blew up the Gorgopotamos viaduct. This bridge was vital for Axis supply lines toward North Africa. The operation required daring coordination among ideologically hostile groups. Its success showed that collaboration against a common enemy was possible. However such moments of unity remained exceptions rather than the rule. As in Yugoslavia, the occupiers in Greece responded with harsh reprisals. Villages suspected of supporting guerrillas faced burnings and mass shootings. Hostages were executed after attacks on German soldiers. Italian forces employed large sweep operations in the countryside. After Italy’s armistice in nineteen forty three, German troops disarmed Italian units and took direct control of former Italian zones. This change increased the intensity of anti guerrilla measures. Yet it also provided the resistance with captured Italian arms and equipment, which significantly expanded their capabilities. The question of collaboration took different forms in Greece. The Germans supported local security battalions to fight communist influence. These units were recruited from anti communist officers, opportunists, and people seeking protection. They framed their role as defense against Bolshevism and banditry. In practice they often carried out counterinsurgency and terror operations against suspected supporters of the Liberation Front. Their existence deepened the polarization of Greek society. Class, ideology, and regional grievances overlapped with the occupation divide. Both Yugoslav and Greek partisan movements integrated women in important ways. Many women became couriers, nurses, and organizers. Others fought as armed guerrillas. Their participation challenged traditional gender roles in conservative rural societies. The partisan platforms promised legal equality, access to education, and political rights for women. After the war these promises would be only partially fulfilled. Yet during the struggle, women’s activism was highly visible and crucial to logistics and intelligence. Religion played a complex role in Balkan resistance and collaboration. In Yugoslavia Orthodox, Catholic, and Muslim institutions responded differently depending on region and leadership. Some priests and imams joined the partisans or sheltered persecuted people. Others aligned with nationalist or collaborationist authorities. The Independent State of Croatia manipulated Catholic symbolism to legitimize its genocidal policies. In Greece the Orthodox Church had figures who blessed resistance fighters and others who cooperated with occupation administrations. For villagers, clergy often served as moral interpreters of the confusing wartime landscape. Ethnic cleansing and genocide formed the darkest backdrop to partisan warfare in the Balkans. In the Independent State of Croatia, Ustaša militias targeted Serbs, Jews, and Roma for extermination, forced conversion, or expulsion. Camps like Jasenovac became sites of mass murder. German forces organized the deportation and killing of almost the entire Jewish community of Salonika. In occupied Serbia, German reprisals included systematic shooting of Jews and Roma as hostages. These crimes radicalized the conflict. Some groups sought revenge against entire communities. Partisans tried to recruit across lines but also struggled to restrain retaliatory violence. Everyday life under occupation shaped attitudes toward all armed groups. Peasants worried about food requisitions from both occupiers and guerrillas. Urban dwellers feared arrests, bombings, and hunger. Villagers often judged partisans and Chetniks not by ideology but by behavior. Did fighters pay for goods or simply seize them. Did they protect the community against raids or provoke destruction. Over time many people supported whichever side seemed capable of bringing security and justice, even temporarily. This pragmatic support could shift as the military balance changed. Strategically the Balkans mattered greatly for Axis logistics. Railways carried mineral resources, oil, and troops between central Europe and the Mediterranean. Partisans targeted these routes relentlessly. They blew up tracks, destroyed tunnels, and attacked bridges. Such actions forced Germany to divert large numbers of troops to guard lines of communication. These units might otherwise have fought on the Eastern Front or in Italy. Allied assessments recognized this draining effect. They considered Balkan resistance as an important contribution to the broader war effort. Allied support, however, was always influenced by political calculations. British policymakers worried about communist dominance in both Yugoslavia and Greece. Yet they could not ignore which forces actually fought the Germans. As partisan successes multiplied, London and Washington increased supplies of weapons, radios, and medical equipment. They dropped liaison teams to coordinate air drops and plan operations. At the same time they tried to encourage cooperation between communist and non communist groups. These efforts often failed due to deep mistrust and incompatible goals regarding postwar power. By nineteen forty three and nineteen forty four the partisan movements began acting as proto governments. In Yugoslavia liberated territories hosted people’s courts and schools. Taxes were collected to support the war effort. Cultural troupes traveled between units, performing plays and songs that promoted new social values. In Greece the Liberation Front organized local elections and assemblies in the mountains. These institutions also managed land disputes and social reforms. Such practices not only sustained resistance but also prepared the ground for postwar political struggles. German retreats created power vacuums across the Balkans. As the Red Army advanced from the east and Allied forces pressed from Italy, Axis garrisons withdrew. Partisan units rushed to seize towns and communication centers. In Yugoslavia Tito’s forces entered Belgrade in coordination with Soviet troops in October nineteen forty four. They quickly moved to disarm Chetnik remnants and other rivals. In Greece German forces pulled out of Athens in October nineteen forty four. The British landed troops to support the return of the Greek government in exile and to contain communist influence. These liberation moments immediately turned into confrontations over state power. In Yugoslavia the partisan leadership convened a new session of the Anti Fascist Council. It declared itself the sole legal authority and abolished the monarchy. Tito’s government began implementing land reform, nationalization, and security measures against perceived enemies. Trials and purges targeted collaborators but also political opponents. Many Chetnik commanders and Ustaša leaders were captured, executed, or fled abroad. For ordinary people, the transition meant both relief from occupation and exposure to a new centralized state.

In Greece the situation was even more contentious. The Liberation Front had strong support in many regions and controlled a large guerrilla army. The government in exile, backed by Britain, wanted to restore prewar institutions with the king returning. Negotiations over integration of resistance forces into a national army broke down. In December nineteen forty four fighting erupted in Athens between communist led forces and British backed government troops. This conflict, known as the December events, marked the opening phase of the Greek civil war. A full scale civil war would rage between nineteen forty six and nineteen forty nine. Comparing the two cases highlights both similarities and differences. In Yugoslavia, the partisans achieved near complete military dominance by the end of the war. They built a federal socialist state that recognized multiple national republics. Their legitimacy derived from both armed struggle and revolutionary transformation. In Greece the communist led resistance emerged from the war popular but politically isolated internationally. British and later American backing for anti communist forces shifted the balance. The outcome there was defeat of the communist side and restoration of a conservative monarchy for a time. The term partisan itself carried distinct meanings in the Balkans after the war. In Yugoslavia former partisans were celebrated as the founding generation of the socialist federation. Memorials, films, and schoolbooks glorified their battles and sacrifices. The image of multiethnic brotherhood in arms became a central state myth. In Greece memory was far more divided. Right wing narratives portrayed communist partisans as threat to national unity and Western orientation. Left wing narratives remembered them as heroes betrayed by foreign intervention and domestic elites. These competing memories shaped politics for decades. It is important to recognize the moral complexities within these histories. Partisans fought occupation and significantly contributed to the defeat of fascist powers. Yet some partisan units committed their own atrocities, especially during chaotic offensives and reprisals. Civilian suffering did not end immediately with liberation. New repressions, forced migrations, and ideological campaigns followed. Scholars today examine both the emancipatory and violent aspects of these movements. They study how ordinary people navigated limited choices under extreme pressure. The Balkan partisan experience also raises broader questions about resistance. What constitutes genuine resistance when groups combine anti occupation goals with civil war agendas. How should we weigh tactical collaboration by certain forces against their long term intentions. To what extent can armed movements create more just societies after victory. The cases of Yugoslavia and Greece show that resistance is never purely military. It always intertwines with visions of social order, state power, and identity. Another enduring lesson lies in the role of geography and society. Mountainous terrain and scattered rural settlements favored guerrilla tactics. But geography alone did not shape outcomes. Political organization, discipline, and ability to offer a credible future mattered greatly. The Yugoslav and Greek communists invested heavily in building parallel institutions, not only fighting units. Their strength came from linking military operations with social programs and political education. Non communist groups often underestimated this dual approach and lost influence over time. External powers left deep imprints on Balkan resistance dynamics. The Soviet Union provided ideological inspiration and later some direct support, especially in Yugoslavia. Britain sought to harness resistance for its strategic goals while limiting revolutionary consequences. The United States gradually entered the region’s politics as the war progressed. Decisions made in London, Moscow, and Washington about recognition and supplies could dramatically affect local balances. Yet even these great powers could not simply dictate outcomes. Local actors leveraged foreign backing while pursuing their own agendas. Today historians use a variety of sources to reconstruct partisan history. Memoirs by fighters offer vivid perspectives but also contain justifications and silences. Occupation records reveal how Axis authorities perceived and fought guerrillas. Allied intelligence files show debates over which groups to support. Oral histories capture how villagers recall partisan visits, reprisals, and survival strategies. Together these materials provide a richer, though still contested, picture of what resistance meant on the ground. The legacy of Balkan partisans also persists in cultural memory. Songs, novels, and films retell battles and dilemmas from different angles. Some emphasize heroism and sacrifice. Others highlight moral ambiguity and personal tragedy. In post Yugoslav states, recent wars have reshaped interpretations of the earlier partisan experience. Nationalist narratives sometimes challenge or replace the older socialist myth of brotherhood. Yet the scale and intensity of wartime mobilization during the nineteen forties remains a shared reference point. When we consider the Balkans during the Second World War, we see more than occupation and rebellion. We see overlapping wars of liberation, revolution, and state formation. Partisan movements in Yugoslavia and Greece confronted Axis armies, domestic rivals, and their own internal tensions. They tied down large numbers of enemy troops and disrupted vital supply lines. They also transformed social and political structures in ways that lasted long after the guns fell silent. Understanding these partisans means holding several truths together. They were both national fighters and ideological actors. They were both liberators and, at times, agents of new forms of coercion. Their choices were constrained by brutal circumstances, yet they also made strategic decisions with long term consequences. By tracing their emergence, battles, and legacies, we gain insight into how societies resist conquest and how new political orders are forged in the crucible of war. The story of the Balkan partisans therefore illuminates a central feature of modern conflict. Resistance movements rarely operate on a single level. They fight enemies, contest allies, and imagine futures simultaneously. In Yugoslavia and Greece, those futures diverged sharply after nineteen forty five. One path led to a socialist federation claiming to balance national equality and central control. The other led to a Western aligned state scarred by civil war and political repression. Both paths emerged from the choices and sacrifices made in the mountains and villages under occupation.