Sudeten Germans

German Bohemians (German: Deutschböhmen und Deutschmährer [ˈdɔʏtʃˌbøːmən] ^ⓘ; Czech: čeští Němci a moravští Němci, lit. 'German Bohemians and German Moravians'), later known as Sudeten Germans (German: Sudetendeutsche [zuˈdeːtn̩ˌdɔʏtʃə] ^ⓘ; Czech: sudetští Němci), were ethnic Germans living in the Czech lands of the Bohemian Crown, which later became an integral part of Czechoslovakia. Before 1945, over three million German Bohemians constituted about 23% of the population of the whole country and about 29.5% of the population of Bohemia and Moravia. Ethnic Germans migrated into the Kingdom of Bohemia, an electoral territory of the Holy Roman Empire, from the 11th century, mostly in the border regions of what was later called the "Sudetenland", which was named after the Sudeten Mountains.

The process of German expansion was known as Ostsiedlung ("Settling of the East"). The name "Sudeten Germans" was adopted during rising nationalism after the fall of Austria-Hungary in the aftermath of First World War. After the Munich Agreement (1938), the so-called Sudetenland became part of Germany.

After the Second World War, most of the German-speaking population (mostly Roman Catholic with relatively few Protestants) was expelled from Czechoslovakia to Germany and Austria.

The area that became known as the Sudetenland possessed chemical works and lignite mines as well as textile, china, and glass factories. The Bohemian border with Bavaria was inhabited primarily by Germans. The Upper Palatine Forest, which extends along the Bavarian frontier and into the agricultural areas of southern Bohemia, was an area of German settlement. Moravia contained patches of "locked" German territory to the north and south. More characteristic were the German language islands, which were towns inhabited by German minorities and surrounded by Czechs. Sudeten Germans were mostly Roman Catholics, a legacy of centuries of Austrian Habsburg rule.

Not all ethnic Germans lived in isolated and well-defined areas; for historical reasons, Czechs and Germans mixed in many places, and Czech-German bilingualism and code-switching was quite common. Nevertheless, during the second half of the 19th century, Czechs and Germans began to create separate cultural, educational, political and economic institutions, which kept both groups semi-isolated from each other. This semi-isolated status continued until the end of the Second World War, when almost all of the ethnic Germans were expelled.

In the English language, ethnic Germans who originated in the Kingdom of Bohemia were traditionally referred to as "German Bohemians". This appellation utilizes the broad definition of Bohemia, which includes all of the three Bohemian crown lands: Bohemia, Moravia and (Austrian) Silesia. In the German language, it is more common to distinguish among the three lands, hence the prominent terms Deutschböhmen (German Bohemians), Deutschmährer (German Moravians) and Deutschschlesier (German Silesians). Even in German the broader use of "Bohemian" is also found.

The term "Sudeten Germans" (Sudetendeutsche) came about during rising ethnic nationalism in the early 20th century, after the fall of the Austro-Hungarian Empire in the First World War. It coincided with the rise of another new term, "the Sudetenland", which referred only to the parts of the former Kingdom of Bohemia that were inhabited predominantly by ethnic Germans. These names were derived from the Sudeten Mountains, which form the northern border of the Bohemian lands. As these terms were heavily used by the Nazi German regime to push forward the creation of a Greater Germanic Reich, many contemporary Germans avoid them in favour of the traditional names.

There have been ethnic Germans living in the Bohemian crown lands since the Middle Ages. In the late 12th and in the 13th century the Přemyslid rulers promoted the colonisation of certain areas of their lands by German settlers from the adjacent lands of Bavaria, Franconia, Upper Saxony and Austria during the Ostsiedlung migration.