On 3 September 1939, in the wake of Germany’s invasion of Poland, British Prime Minister Neville Chamberlain took to the airwaves to proclaim a state of war between Britain and Germany.
He did so reluctantly, as is evident by this broadcast, and in the knowledge that he was committing Britain to a long and bloody struggle.
This is one of the many key dates of World War Two, and brought Britain together with France into the struggle on Germany’s Western Front that would last until the end of the war. However, initially the British and French did little to come to Poland’s assistance, instead opting for a defensive strategy that was labelled ‘The Phony War’ with no major military operations. However, the defensive warfare of World War One was no longer valid, and the German offensive ‘Blitzkrieg’ strategy led to them and the Axis powers occupying most of mainland Europe by the end of 1940... (see more at: http://madefromhistory.com/)
On September 1, 1939 German troops swarmed across the Polish border and unleashed the first Blitzkrieg the world had seen. Hitler had been planning his attack since March - ever since German troops occupied the remainder of Czechoslovakia. The Poles suspected as much and readied their defenses. Unfortunately the Poles based their defensive strategy on the experiences of World War I. Mobility was crucial - mobility provided by cavalry troops the Poles considered the best in the world. Indeed, their horsemen were probably the world's best - but horses offered little defense against tanks.
Britain and France had sworn to defend Poland. Honoring these obligations, the two countries sent ultimatums to Hitler demanding his withdrawal from Poland. Hitler declined to respond. On September 3, Prime Minister Chamberlain went to the airwaves to announce to the British people that a state of war existed between their country and Germany. World War II had begun.
Unfortunately Chamberlain's action was little help to the Poles. German troops advanced steadily. The final blow came on September 17 when Soviet forces under terms of a secret agreement with Germany marched into Poland from the East. Warsaw surrendered on September 27. By October 6, it was all over. Poland had ceased to exist as a country.
Prime Minister Neville Chamberlain announces Britain's declaration of war on Germany, September 3, 1939