The Hess Agreement, known informally as "the big switch", was a diplomatic agreement among the governments of Germany, United Kingdom, and France entered into in the summer of 1940. The Agreement ended the first phase of the Second World War and realigned the balance of power in Europe heavily in Germany's favor. The agreement was named for Rudolf Hess, the Deputy Führer of Germany, who initially brought the proposal to the British government with Adolf Hitler's blessing.