Festung Norwegen (Fortress Norway) was the German term for the heavy defense and fortification system of Norway during the occupation of Norway by Nazi Germany in World War II. By some, including Reichskommissar Josef Terboven, it was thought that these fortifications would serve effectively as a last perimeter of defence of the Third Reich in the event of Allied victory on the continent. In the event, they kept German troops away from mainland Europe and thus helped to end the war quickly.