Coming just two decades after the last great global conflict, the Second World War was the most widespread and deadliest war in history, involving more than 30 countries and resulting in more than 50 million military and civilian deaths (with some estimates as high as 85 million dead). Sparked by Adolf Hitler’s invasion of Poland in 1939, the war would drag on for six deadly years until the final Allied defeat of both Nazi Germany and Japan in 1945.
