1939–1940. Germany has already invaded Austria and Czechoslovakia. But it's only when Hitler takes Poland that the Second World War begins in earnest.

1941. The war is intensifying, and the Axis powers seem unstoppable. Hitler sends troops to the Soviet border to launch Operation Barbarossa.

1942. The war has engulfed the entire world, and the Germans are winning. Until slowly, after the Battle of Stalingrad, the tide starts to turn.

1943. Changing tactics, the Allies venture into enemy territory. But despite heavy bombing, they struggle to gain a foothold in "Fortress Europe."

1944. The Allies decide that invading Nazi-occupied Europe is their only option. On D-Day, 100,000 soldiers cross the Channel to take back France.