World War II was the deadliest global military conflict in the history of mankind. Large number of nations across the world were involved in the war and split along two opposing military alliances - the Allies (Britain, U.S and Soviet Union as the major powers) and the Axis (Germany, Italy and Japan as the major powers). The war started in Sept 1939 with German invasion of Poland. During the course of the war, more than 72 million people, largely civilians were killed. The war saw the use of new technologies such as atomic bombs, guided missiles and rockets. It ended in 1945, creating a new world order dominated by the United States and Soviet Union.