 After the Polish Campaign, in October 1939, the planners of the "Oberkommando der Luftwaffe" ("Luftwaffe" High Command) and the "Oberkommando der Wehrmacht" (Supreme Command of the Armed Forces) turned their attentions to Western Europe.The German offensive—named "Unternehmen Gelb" (Operation Yellow), and also known as the Manstein Plan—began in the West on 10 May 1940.The central campaign—the Battle of France—ended in Allied defeat and the destruction of the main French Army forces.