After the First World War the Treaty of Versailles placed strict terms on Germany to prevent it from threatening its neighbours. From 1933 the new German leader, Adolf Hitler, began to challenge these restrictions which created a growing level of tension in Europe.
First he moved troops back into the Rhineland area of Germany in March 1936 – this was supposed to be a demilitarised area between Germany and France.
Next in 1938 he took over neighbouring areas countries which had German-speaking populations, including Austria, Memel and then the Sudetenland region of Czechoslovakia.
By 1939 the whole of Czechoslovakia was under German control, either directly or through puppet leaders whom Hitler controlled. By the autumn of 1939 he had his eyes on Poland.
On September 1st German forces invaded Poland. Two days later Britain and France declared war on Germany. They had promised to defend Poland against German attack.
In reality, Britain and France could do little to help Poland. German forces used tactics known as Blitzkrieg, or Lightning War. Tanks, aircraft and motorised vehicles co-ordinated by radio allowed the Germans to make rapid advances.
When the USSR invaded Poland from the East on September 17th, it was only a matter of time before the country was carved up between the two invaders.
The Polish capital, Warsaw, fell on September 27th. After the fall of Poland there was a relatively quiet period sometimes called the Phoney War. This gave Britain valuable time to make preparations for the real war once it began in April 1940 when Hitler invaded Denmark and Norway. He wanted control of the ports in these countries to use as naval bases.
Britain sent forces to Norway but it finally surrendered in June 1940.
May 1940 the Germans were already advancing on France, but wished to avoid the fortified border between the two countries known as the Maginot Line. Instead of attacking France directly the Germans invaded through the neutral countries of the Netherlands and Belgium.
Blitzkrieg tactics again proved devastatingly effective. By late May British and French forces were trapped in a large pocket of Northern France. On May 26th there was a mass evacuation from Dunkirk. Belgium surrendered the next day and by June 14th the Germans were in Paris. France surrendered soon afterwards.
Northern France was in German hands. They allowed the south to be run by a French government based in Vichy.
After the fall of France Hitler’s attention turned to Britain. His biggest problem was the Royal Navy, which would destroy his troop ships as they tried to cross the Channel. The only way to destroy the navy was by air. To do this, he needed to defeat the RAF. So began the Battle of Britain.
From June to October 1940 German bombers tried to destroy the airfields which the RAF used as bases. By October over 1000 planes on each side had been lost but the RAF was gaining the upper hand.
At this point German tactics changed. They began bombing British cities, causing huge damage and killing thousands. Despite this, it was clear that Hitler’s plans to invade Britain were now on hold. The main focus of the war would now turn to other fronts.