High Quality Content by WIKIPEDIA articles! This is a timeline of events that stretched over the period of World War II. World War II, or the Second World War, was a global military conflict between 1939 and 1945, which involved most of the world's nations, including all great powers, organised 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.