The departments of Nord and Pas-de-Calais were attached to the military administration in Belgium and Northern France, which was also responsible[1] for civilian affairs in the 20-kilometre (12 mi) wide zone interdite along the Atlantic coast.

War refugees were prohibited from returning to their homes, and it was intended for German settlers and annexation[2] in the coming Nazi New Order (Neue Ordnung).

The French government will immediately direct all officials and administrators of the occupied territory to comply with the regulations of, and to collaborate fully with, the German military authorities.

In order to suppress partisans and resistance fighters, the military administration cooperated closely with the Gestapo, the Sicherheitsdienst (SD), the intelligence service of the SS, and the Sicherheitspolizei (SiPo), its security police.

It also had at its disposal the support of the French authorities and police forces, who had to cooperate per the conditions set in the armistice, to round up Jews, anti-fascists and other dissidents, and vanish them into Nacht und Nebel, "Night and Fog".

The number of troops increased when the threat of Allied invasion began looming large, with the Dieppe raid marking its real beginning.

After the invasion of the Soviet Union in June 1941, the French communist party, hitherto under orders from the Comintern to remain passive against the German occupiers, began to mount actions against them.

De Gaulle sent Jean Moulin back to France as his formal link to the irregulars throughout the occupied country to coordinate the eight major Résistance groups into one organisation.

The resistance intensified after it became clear the tide of war had shifted after the Reich's defeat at Stalingrad in early 1943 and, by 1944, large remote areas were out of the German military's control and free zones for the maquisards, so-called after the maquis shrubland that provided ideal terrain for guerrilla warfare.

By the eve of the liberation, numerous factions of nationalists, anarchists, communists, socialists and others, counting between 100,000 and up to 400,000 combatants, were actively fighting the occupation forces.

Supported by the Special Operations Executive and the Office of Strategic Services that air-dropped weapons and supplies, as well as infiltrating agents like Nancy Wake who provided tactical advice and specialist skills like radio operation and demolition, they systematically sabotaged railway lines, destroyed bridges, cut German supply lines, and provided general intelligence to the allied forces.

[13]: 23 After their victory in June 1940, the occupation authorities first relied on the German embassy in Paris (Hôtel Beauharnais) to monitor publications, shows, and radio broadcasts.

[13]: 23  There were Sonderführers (special directors) in charge of particular areas: censorship of shows and plays, publishing and press, cinematographic works, and public advertising and speeches.

Faced with these difficulties in everyday life, the government answered by rationing, and creating food charts and tickets which were to be exchanged for bread, meat, butter and cooking oil.

The official ration provided starvation level diets of 1,300 or fewer calories a day, supplemented by home gardens and, especially, black market purchases.

In the absence of meat and other foods including potatoes, people ate unusual vegetables, such as Swedish turnip and Jerusalem artichoke.

[20] Many Parisians could not get over the shock experienced when they first saw the huge swastika flags draped over the Hôtel de Ville and flying on top of the Eiffel Tower.

[22]Ousby wrote that by the end of summer of 1940: "And so the alien presence, increasingly hated and feared in private, could seem so permanent that, in the public places where daily life went on, it was taken for granted".

[24] With nearly 75,000 inhabitants killed and 550,000 tons of bombs dropped, France was, after Germany, the second most severely bomb-devastated country on the Western Front of World War II.

In the private Catholic sector, many school directors hid Jewish children (thus saving their life) and provided education for them until the Liberation.

Edith Piaf lived above L'Étoile de Kléber, a famous bordello on the Rue Lauriston, which was near the Carlingue headquarters and was often frequented by German troops.

[30] The use and abuse of Paris in the visitations of German forces during the Second World War led to a backlash; the intensive prostitution during the occupation made way for the Loi de Marthe Richard in 1946, which closed the bordellos and reduced raunchy stage shows to mere dancing events.

In addition to work camps for factories, agriculture, and railroads, forced labour was used for V-1 launch sites and other military facilities targeted by the Allies in Operation Crossbow.

There were German reprisals against civilians in occupied countries; in France, the Nazis built an execution chamber in the cellars of the former Ministry of Aviation building in Paris.

13,152 Jews residing in the Paris region were victims of a mass arrest by pro-Nazi French authorities on 16 and 17 July 1942, known as the Vel' d'Hiv Roundup, and were transported to Auschwitz where they were killed.

[32] Overall, according to a detailed count drawn under Serge Klarsfeld, slightly below 77,500 of the Jews residing in France died during the war, overwhelmingly after being deported to death camps.

Thanks to Lend-Lease, it was well equipped and well supplied despite the economic disruption brought by the occupation, and it grew from 500,000 men in the summer of 1944 to more than 1.3 million by V-E day, making it the fourth largest Allied army in Europe.

On 22 April 1945, it captured the Sigmaringen enclave in Baden-Württemberg, where the last Vichy regime exiles, including Marshal Pétain, were hosted by the Germans in one of the ancestral castles of the Hohenzollern dynasty.

Collaborators were put on trial in legal purges (épuration légale), and a number were executed for high treason, among them Pierre Laval, Vichy's prime minister in 1942–44.

Marshal Pétain, "Chief of the French State" and Verdun hero, was also condemned to death (14 August 1945), but his sentence was commuted to life three days later.