British Empire in World War II

When the United Kingdom declared war on Nazi Germany at the outset of World War II it controlled to varying degrees numerous crown colonies, protectorates and the Indian Empire. It also maintained unique political ties to four independent Dominions—Australia, Canada, South Africa, and New Zealand—as part of the Commonwealth. In 1939 the British Commonwealth was a global superpower, with direct or de facto political and economic control of 25% of the world's population, and 30% of its land mass.

The contribution of the British Empire and Commonwealth in terms of manpower and materiel was critical to the Allied war effort. From September 1939 to mid-1942 Britain led Allied efforts in almost every global military theatre. Commonwealth forces (United Kingdom, Colonial, Imperial and Dominion), totalling close to 15 million serving men and women, fought the German, Italian, Japanese and other Axis armies, air forces and navies across Europe, Africa, Asia, and in the Mediterranean Sea and the Atlantic, Indian, Pacific and Arctic Oceans. Commonwealth forces fought in Britain, and across Northwestern Europe in the effort to slow or stop the German advance. Commonwealth airforces fought the Luftwaffe to a standstill over Britain, and its armies fought and destroyed Italian forces in North and East Africa and occupied several overseas colonies of German-occupied European nations. Following successful engagements against Axis forces, Commonwealth troops invaded and occupied Libya, Italian Somaliland, Eritrea, Ethiopia, Iran, Iraq, Syria, Lebanon, Iceland, the Faroe Islands, and Madagascar.

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