Learn about Britain's involvement in WWII in this excerpt from In Their Own Words: Queen Elizabeth II. The war begins on September 1, 1939 with Hitler’s invasion of Poland. Two days later, Britain declares war on Germany. Monarchs from all over Europe flee their countries, but Elizabeth’s mother declares that the King will never leave the country and neither will she or her daughters. The British people endure the daily death and devastation of “The Blitz.” In the fall of 1940, Elizabeth makes her first public speech on the radio.