What was the biggest event in 1940?

The biggest event in 1940 was World War II, particularly the fall of France to Nazi Germany. In May and June, German forces executed a rapid invasion, leading to the surrender of French troops and the establishment of the Vichy regime. This event significantly shifted the balance of power in Europe and marked a pivotal moment in the war, prompting increased involvement from the Allies, including Britain and the United States. The fall of France also had lasting implications for global politics and military strategy throughout the conflict.