Treaty of Versailles: The peace treaty signed by Germany and the Allied Powers after World War I which established new national boundaries, including the creation of the Polish Corridor.
Interwar Period: The period between World War I and World War II, during which tensions over territorial changes like the Polish Corridor contributed to rising hostilities.
League of Nations: An international organization formed after World War I with the goal of maintaining world peace; its inability to resolve issues like those surrounding the Polish Corridor contributed to its eventual failure.