The Second World War[1] officially began on 1 September 1939, with the German invasion of Poland. Britain and France declared war on the Nazi Third Reich on 3 September 1939. Seven days later, on 10 September 1939, the Parliament of Canada likewise declared war on Germany, the country's first independent declaration of war[2] and the beginning of Canada's participation in the largest combined national effort in its history. By the war's end, over 1 million citizens would serve in military uniform, and Canada would possess the fourth-largest air force and third-largest naval surface fleet in the world.[3]