The Klaipėda Region or Memel Territory was defined by the Treaty of Versailles in 1920 when it was put under the administration of the Council of Ambassadors. The Memel Territory was to remain under the control of the League of Nations until a future day when the people of the region would be allowed to vote on whether the land would return to Germany or not. The then predominantly ethnic German Memel Territory (Prussian Lithuanians and Memellanders constituted the other ethnic groups), situated between the river and the town of that name, was occupied by Lithuania in the Klaipėda Revolt of 1923.