A Day That Shook The World: Germany invades Poland

(Hulton Archive/Getty Images)

On 1 September 1939 Germany invaded Poland, prompting Britain and France to declare war three days later.

In a terrifying demonstration of the power of the Blitzkrieg doctrine, German armed forces overwhelmed those of Poland in a matter of hours, setting the stage for nearly six years of bitter global conlict.

Watch original footage from the invasion in this British Pathé video, above.