German Bohemians (, i.e. German Bohemians and German Moravians), later known as Sudeten Germans, were ethnic Germans living in the Czech lands of the Bohemian Crown, which later became an integral part of Czechoslovakia in which before 1945 over three million German Bohemians inhabited, about 23 percent of the population of the whole country and about 29.5 percent 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 after the First World War. After the Munich Agreement, the so-called Sudetenland became part of Germany.