The Sudetenland was a source of tension between Czechoslovakia and Germany in the interwar period. The Sudeten German Party (SdP), led by Konrad Henlein, advocated for greater autonomy and eventually the secession of the Sudetenland from Czechoslovakia. The SdP received support from Nazi Germany, which saw the Sudetenland as part of its Lebensraum ("living space") and used the issue to pressure Czechoslovakia.
In 1938, the Sudetenland crisis led to the Munich Agreement, in which Czechoslovakia was forced to cede the Sudetenland to Germany. The Munich Agreement was widely seen as a failure of the policy of appeasement towards Nazi Germany. The annexation of the Sudetenland paved the way for the further dismemberment of Czechoslovakia and the eventual outbreak of World War II.