place the following world war two events in chronological order from oldest to most recent

1. Invasion of Poland (September 1, 1939)

2. Battle of Stalingrad (August 23, 1942 – February 2, 1943)
3. D-Day (June 6, 1944)
4. Atomic bombings of Hiroshima and Nagasaki (August 6 and 9, 1945)