World War Two

World War Two was a global military conflict which involved a majority of the world's nations, including all of the great powers,organized into two opposing military alliances: the Allies and the Axis. The war involved the mobilisation of over 100 million military personnel, making it the most widespread war in history. In a state of "total war", the major participants placed their complete economic, industrial, and scientific capabilities at the service of the war effort, erasing the distinction between civilian and military resources. Over seventy million people, the majority of them civilians, were killed, making it the deadliest conflict in human history. The start of the war is generally held to be in September 1939 with the German invasion of Poland and subsequent declarations of war on Nazi Germany by most of the countries in the British Commonwealth and France. In an effort to maintain international peace, the Allies formed the United Nations, which officially came into existence on October 24, 1945.