Under the Treaty of Versailles, the highly industrialized Saar Basin, including the Saar Coal District (), was to be occupied and governed by the United Kingdom and France under a League of Nations mandate for a period of fifteen years.
The Territory comprised the portions of the Prussian Rhenish Trier Region and the Bavarian district of the Palatinate, which had a significant number of the miners, working in the Saar coal mines, among the population.