Sudetenland (Czech and Slovak: Sudety, Polish: Kraj Sudetów) is the German name (used in English in the first half of the twentieth century) for the northern, southwest and western regions of Czechoslovakia inhabited mostly by ethnic Germans, specifically the border areas of Bohemia, Moravia, and those parts of Silesia located within Czechoslovakia.
The name is derived from the Sudetes mountains, though the Sudetenland extended beyond these mountains which run along the border to Silesia and contemporary Poland. Sudeti montes was already used on Ptolemaios' map of the 2nd century. The German inhabitants were called Sudeten Germans (German: Sudetendeutsche;, Czech: Sudetští Němci; Polish: Niemcy Sudeccy). The German minority in Slovakia, the Carpathian Germans, is not included in this ethnic category.
The current Czech regions of Karlovy Vary, Liberec, Moravia-Silesia and Ústí nad Labem were situated mostly inside the former Sudetenland.
Read more about Sudetenland: History