The end of World War I, in 1918, brought about the breakup of the multiethnic Austro-Hungarian Empire into its historical components, one of them being Bohemian kingdom, forming the western part of newly created Czechoslovakia. Czech politicians insisted on the traditional boundaries of the Bohemian Crown, according to Uti possidetis juris. This meant that the new Czech state would have defensible mountain boundaries with Germany, but also that the highly industrialized settlement areas of three million ethnic Germans would be separated from Austria and come under Czech control.