Battle of France

The Battle of France (French: bataille de France; 10 May – 25 June 1940), also known as the Western Campaign (German: Westfeldzug), the French Campaign (Frankreichfeldzug, campagne de France) and the Fall of France, during the Second World War was the German invasion of the Low Countries (Belgium, Luxembourg and the Netherlands) and France. The plan for the invasion of the Low Countries and France was called Fall Gelb (Case Yellow or the Manstein plan). Fall Rot (Case Red) was planned to finish off the French and British after the evacuation at Dunkirk. The Low Countries and France were defeated and occupied by Axis troops down to the Demarcation line.

On 3 September 1939, France and Britain declared war on Nazi Germany, over the German invasion of Poland on 1 September. In early September 1939, the French army began the limited Saar Offensive but by mid-October had withdrawn to the start line. On 10 May 1940, Wehrmacht armies invaded Belgium, Luxembourg, the Netherlands and parts of France.

In Fall Gelb (Case Yellow), German armoured units advanced through the Ardennes, crossed the Meuse and raced down the Somme valley, cutting off and surrounding the Allied units that had advanced into Belgium to meet the German armies there. British, Belgian and French forces were pushed back to the sea by the Germans where the British and French navies evacuated the encircled elements of the British Expeditionary Force (BEF) and the French and Belgian armies from Dunkirk in Operation Dynamo.

German forces began Fall Rot (Case Red) on 5 June 1940. The remaining Allied divisions in France, sixty French and two British, made a determined stand on the Somme and Aisne rivers but were defeated by the German combination of air superiority and armoured mobility. Italy entered the war on 10 June 1940 and began the Italian invasion of France. German armies outflanked the Maginot Line and pushed deep into France, occupying Paris unopposed on 14 June. After the flight of the French government and the collapse of the French Army, German commanders met with French officials on 18 June to negotiate an end to hostilities.

On 22 June 1940, the Second Armistice at Compiègne was signed by France and Germany. The fascist and collaborationist Vichy government led by Marshal Philippe Pétain replaced the Third Republic and German military occupation began along the French North Sea and Atlantic coasts and their hinterlands. After the armistice, Italy occupied a small area in the south-east of France. The Vichy regime retained the zone libre (free zone) in the south. Following Operation Torch, the Allied invasion of French North Africa, in November 1942, in Case Anton, the Germans and Italians took control of the zone until France was liberated by the Allies in 1944.

During the 1930s, the French built the Maginot Line, fortifications along the border with Germany.^{[page needed]} The line was intended to economise on manpower and deter a German invasion across the Franco–German border by diverting it into Belgium, which could then be met by the best divisions of the French Army. The war would take place outside French territory, avoiding the destruction of the First World War. The main section of the Maginot Line ran from the Swiss border and ended at Longwy; the hills and woods of the Ardennes region were thought to cover the area to the north.

General Philippe Pétain declared the Ardennes to be "impenetrable" as long as "special provisions" were taken to destroy an invasion force as it emerged from the Ardennes by a pincer attack. The French commander-in-chief, Maurice Gamelin, also believed the area to be safe from attack, noting it "never favoured large operations". French war games, held in 1938, of a hypothetical German armoured attack through the Ardennes, left the army with the impression that the region was still largely impenetrable and that this, along with the obstacle of the Meuse River, would allow the French time to bring up troops into the area to counter any attack.

In 1939, the United Kingdom and France offered military support to Poland in the likely case of a German invasion. At dawn on 1 September 1939, the German invasion of Poland began. France and the United Kingdom declared war on 3 September, after an ultimatum for German forces to immediately withdraw from Poland was not answered. Australia and New Zealand also declared war on 3 September, South Africa on 6 September and Canada on 10 September. While British and French commitments to Poland were met politically, the Allies failed to fulfil their military obligations to Poland, later called the Western betrayal by the Poles. The possibility of Soviet assistance to Poland had ended with the Munich Agreement of 1938, after which the Soviet Union and Germany eventually negotiated the Molotov–Ribbentrop Pact, which included an agreement to partition Poland. The Allies settled on a long-war strategy in which they would complete the rearmament plans of the 1930s while fighting a defensive land war against Germany and weakening its war economy with a trade blockade, ready for an eventual invasion of Germany.