Final answer:
The Sudetenland is the northern portion of Czechoslovakia inhabited by German speakers. Adolf Hitler demanded its annexation in 1938, leading to the occupation of the rest of Czechoslovakia in 1939.
Step-by-step explanation:
The Sudetenland refers to the northern portion of Czechoslovakia, which was inhabited mostly by German speakers. It is known for the international crisis that occurred in 1938 when Adolf Hitler demanded the annexation of the Sudetenland to protect its German population.
The British and French governments agreed to this demand at the Munich Conference, which ultimately led to the occupation of the rest of Czechoslovakia by German troops in 1939.