World War II 1939–1941: Blitzkrieg, Invasions and Occupation

World War II: 1939–1941 Early Axis Campaigns

World War II began on 1 September 1939, when Germany invaded Poland. Hitler was convinced that France and Britain would follow a conciliatory attitude, but France and Britain declared war on Germany on September 3 after issuing an ultimatum. Thus began a new war in Europe, what is known as the blitzkrieg.

War Theaters and Blitzkrieg Tactics

The war took place in multiple theaters: Europe, the Mediterranean and Atlantic, the Asian front, the Pacific islands, and North Africa. After the declaration of war, German motorized units and squadrons of the German Luftwaffe annihilated much of the outdated Polish army and rapidly reached Warsaw.

Norway and Denmark, April 1940

In April 1940, the Germans invaded Norway and Denmark to prevent Allied forces from blocking iron ore supplies and to secure strategic positions.

Invasion of France and the Maginot Line

Hitler's next target was France. The French had built a defense, the Maginot Line, on the border with Germany and had concentrated their troops there, therefore expecting a German attack through that area. Instead, the Germans surprised them by sending tanks through the Ardennes region, which had been considered impassable by the French.

Rapid Western Advances

In just two weeks, the German army brought an end to resistance in the Netherlands, Belgium, and France, and pushed back the British Expeditionary Force. In a few days the British were forced to evacuate from Dunkirk — more than 300,000 men were evacuated.

Paris was occupied on June 13 and France signed an armistice on June 22. The country was divided: the north and west were occupied by the Germans, while the remainder, with its capital in Vichy, remained under the French government of Marshal Pétain (1856–1951) and became a collaborationist state; French colonies remained under French authority.

French Resistance and British Resolve

From London, General Charles de Gaulle called on the French to organize a movement of resistance. Meanwhile, in the United Kingdom, Winston Churchill led Britain: the Royal Air Force defeated the German Luftwaffe in the Battle of Britain, and British aviation prevented the German plan to invade the island.

Balkans and New Operations

Hitler intervened in the Balkans, conquering Yugoslavia and Greece during the spring in a new lightning operation. Romania, Bulgaria, and Hungary, which had pro‑Nazi governments, became allies of the Reich in 1941. Finland also aligned with Germany against the USSR.

Summary of Key Early Events

• 1 Sept 1939: Germany invades Poland; Britain and France declare war (3 Sept).
• April 1940: Germany invades Norway and Denmark.
• 1940: German breakthrough via the Ardennes; Netherlands, Belgium and France fall quickly.
• June 1940: Dunkirk evacuation; Paris occupied; armistice divides France (Vichy government).
• Battle of Britain: RAF repels the Luftwaffe, thwarting invasion plans.
• Spring campaigns in the Balkans; Romania, Bulgaria and Hungary align with the Reich; Finland co‑operates against the USSR.

Note: This account preserves the original sequence and content while correcting spelling, grammar, and capitalization for clarity.