Karlovy Vary
The city was in Austria-Hungary, and the people who lived there were mainly German-speaking. Bohemia was transferred to the new state of Czechoslovakia after World War I. The existence of such German-speaking peoples outside of Germany was used by Hitler as a reason to invade the Sudetenland (the German-speaking part of Bohemia and Moravia), which Germany did in 1938. This was a result of the Munich Agreement. This event was a prelude to World War II.