What crucial lesson was learned in the battle of britain

Hitler could be defeated.

Explanation:

The Battle of Britain was the air force battle between Royal Air Force (RAF) and Luftwaffe. RAF was Britain's Air Force whereas Luftwaffe was Germany's.

During the World War 2, Hitler tried to advance and invade Great Britain after invading France and most of Europe. In this plan of invasion, Hitler and Nazi planned an attack on the Airforce of the Great Britain. The Battle of Britain began on 10th July 1940 and ended on 31st October 1940.

The lesson that was learned from this battle was that Hitler and Nazi could be defeated as Britain gained the victory in this battle on 31st October 1940