- The Second World War began in September 1939 when Germany invaded Poland. It involved most of the world's nations fighting as part of the Axis powers led by Germany, Italy and Japan or the Allied powers led by the UK, USSR and USA. Over 60 million people were killed making it the deadliest war in history.
- Hitler rose to power in Germany after writing Mein Kampf and gaining popularity. As Chancellor, he rapidly expanded Germany's military and violated the Treaty of Versailles. Germany invaded Poland in 1939 starting the war.
- The war was fought in two main theaters - Europe and the Pacific. Germany quickly conquered much of Europe but was eventually defeated by the Allied invasion of Normandy in 1944. Japan was defeated