September 29, 1938
September 29–30, 1938: Germany, Italy, Great Britain, and France sign the Munich agreement, by which Czechoslovakia must surrender its border regions and defenses (the so-called Sudeten region) to Nazi Germany. German troops occupy these regions between October 1 and 10, 1938.
Hitler had threatened to unleash a European war unless the Sudetenland, a border area of Czechoslovakia containing an ethnic German majority, was surrendered to Germany. The leaders of Britain, France, and Italy agreed to the German annexation of the Sudetenland in exchange for a pledge of peace from Hitler. Czechoslovakia, which was not a party to the Munich negotiations, agreed under significant pressure from Britain and France.