Germany lost 13% of its territory under the Treaty of Versailles, including areas such as Alsace-Lorraine which was returned to France, and West Prussia and Posen which returned to Poland. The reunification of Germany and Austria was now forbidden, and the Rhineland became a demilitarised zone. All of Germany's colonies were now controlled and supervised by countries under the League of Nations. Collectively, Germany's lost territory accounted for 6.5 million people (12% of its population), 15% of its agricultural production and 15% of its coal.