Resistance movements during World War II occurred in every occupied country by a variety of means—ranging from non-cooperation, disinformation and propaganda, to hiding crashed pilots and even to outright warfare and the recapturing of towns. In many countries, resistance movements were sometimes also referred to as “The Underground.”

Among the most notable resistance movements were the Polish Resistance, including the Polish Home Army, Leśni and the whole Polish Underground State; the Soviet partisans, the Italian Resistenza led mainly by the Italian CLN; the French Resistance, Yugoslav Partisans, Belgian Resistance, Norwegian Resistance, Greek Resistance and the Dutch Resistance.

Many countries had resistance movements dedicated to fighting the Axis invaders, and Germany itself also had an anti-Nazi movement. Although Britain was not occupied during the war, the British made preparations for a British resistance movement, called the Auxiliary Units in the event of a German invasion. Various organizations were also formed to establish foreign resistance cells or support existing resistance movements, like the British SOE and the American OSS (the forerunner of the CIA).

There were also resistance movements fighting against the Allied invaders. In Italian East Africa, after the Italian forces were defeated during the East African Campaign, some Italians participated in a guerrilla war against the British (1941–1943). The German Nazi resistance movement (Werwolf) never amounted to much. The Forest Brothers of Estonia. Latvia and Lithuania included many fighters who operated against the Soviet occupation of the Baltic States into the 1960s. During or after the war, similar anti-Soviet resistance rose up in places like Romania, Poland, Bulgaria, Ukraine and Chechnya. While the Japanese were famous for "fighting to the last man," Japanese holdouts tended to be individually motivated and there is little indication that there was any organized Japanese resistance after the war.

After the first shock following the Blitzkrieg, people slowly started to get organized, both locally and on a larger scale, especially when Jews and other groups were starting to be deported and used for the Arbeitseinsatz (forced labor for the Germans). Organization was dangerous; so much resistance was done by individuals. The possibilities depended much on the terrain; where there were large tracts of uninhabited land, especially hills and forests, resistance could more easily get organized undetected. This favored in particular the Soviet partisans in Eastern Europe. In the much more densely populated Netherlands, the Biesbosch wilderness could be used to go into hiding. In northern Italy, both the Alps and the Apennines offered shelter to partisan brigades, though many groups operated directly inside the major cities.

There were many different types of groups, ranging in activity from humanitarian aid to armed resistance, and sometimes cooperating to a varying degree. Resistance usually arose spontaneously, but was encouraged and helped mainly from London and Moscow.

WOMEN OF THE RESISTANCE

Women were generally confined to underground roles in the French Resistance network.

Lucie Aubrac, who has become a symbol of the French Resistance within France, never had a clearly defined role in the hierarchy of the movement, which in her case involved the regional Southern Liberation. Hélène Viannay, more highly educated than her husband Philippe Viannay, the founder of the Défense de la France, did not write one single article for the clandestine newspaper of the same name, nor did the other companions of the chiefs of the Défense de la France, although they did take part in meetings to edit the newspaper. On the other hand, Suzanne Buisson, cofounder of the Comité d'action socialiste (CAS) was the treasurer until her arrest. Only one woman, Marie-Madeleine Fourcade, was a head of a network (by leading the British to believe that the true head of the Alliance network was actually a man). No woman ever led a movement, or a maquis (guerilla group) or a Liberation Committee; none was installed as a Commissioner within the Provisional Government of the Republic of France or a Minister of the Liberation.

Only a limited minority took part in the armed battles. Although women were typical partisan resistance fighters in Italy, Greece, Yugoslavia and the occupied USSR, feared and as numerous as men, they were a small minority in the maquis in France. It has been speculated that this may have been influenced by the fact that French women were not subject to the Service du travail obligatoire (Compulsory Work Service; STO), as were women in other occupied territories.

Women organized demonstrations of housewives in 1940, were active in the comités populaires of the clandestine PCF, and ever present with encouragement and material aid for strikers, as in the Nord-Pas-de-Calais in May 1941, as well as supporting the maquis. They were indispensable as typists, and above all as liaison agents—in part because the Germans distrusted women less, and also because the numerous identification controls against resistors of STO did not apply to them. Historian Olivier Wieviorka emphasizes that the strategy of these movements was often, in fact, to put women into missions that required visibility, since they were less exposed to repression: the Vichy government of occupied France and the German military were not able to fire on French women demanding food for their children.

Some of the most prominent women in the French Resistance were Marie-Hélène Lefaucheux who was chief of the women's section of the Organisation civile et militaire. She was also a member of the Paris Liberation Committee. Following the French Liberation, she was a Deputy and then Senator of the French government. Touty Hiltermann played a decisive role in the establishment and functioning of the Dutch-Paris movement. Germaine Tillion became head of the Hauet-Vildé Resistance network from 1941 to 1942, later approved by the larger Resistance network Groupe du musée de l'Homme. Hélène Studler organized réseau d'évasions, networks for smuggling dissidents out of France. Thousands of prisoners and Resistance members escaped to freedom through her work. She organized the escape of François Mitterrand, the future President of France; Boris Holban, founder of the network FTP-MOI in March 1942; and General Henri Giraud on 17 April 1942.

It is also worth noting that innumerable clandestine combatants survived the war as a couple, and that their Resistance participation would have been impossible or unsurvivable without the support of their companion at their side: Cécile Rol-Tanguy and husband Henry, Lucie Aubrac and husband Raymond, Paulette Kriegal-Valrimond and husband Maurice, Hélèn Viannay and husband Philippe, Marie-Hélène Lefaucheux and husband Pierre, Cletta Mayer and husband and many others were inseparable.

There were numerous women in the Resistance who married and had children entirely clandestinely, without interrupting their Resistance struggle. Some saved the lives of their husbands, such as Lucie Aubrac or Marie-Hélène Lefaucheux. Others shared their struggle up to torture, deportation and death, such as Madeleine Truel. The famous Convoi des 3100 of 24 January 1943, included many female resisters, communists and widows of men shot by the occupation regime, including Maï Politzer, wife of Georges Politzer or Hélène Solomon, daughter of the great scholar Paul Langevin and wife of writer Jacques Solomon.