In early 1935, the League of Nations facilitated a plebiscite in the Saarland region, which had been governed jointly by the United Kingdom and France since the end of World War I. The region's fate was determined by the Treaty of Versailles, which temporarily assigned Saarland to this administration following Germany's defeat. The plebiscite aimed to ascertain the will of the Saarlanders regarding their future: whether they wished to remain under the League's mandate or reunite with Germany. On January 13, voters turned out in large numbers, with 90.3% favoring the latter option, showcasing a strong sentiment for reunification with Germany, driven by cultural, historical, and national ties to the German state. The overwhelmingly positive response highlighted the local population's discontent with foreign administration and their desire to return to their homeland.

The plebiscite's high turnout and decisive results illustrated the complexities of post-World War I territorial adjustments. Saarland had substantial coal resources and its fate was economically significant for both Germany and France, as it would impact the balance of industrial power in post-war Europe. Following the plebiscite, Saarland was re-integrated into Germany on March 1, leading to economic implications and diplomatic tensions. The event foreshadowed the growing assertiveness of Nazi Germany and was indicative of the socio-political landscape in Europe as tensions began to rise ahead of World War II. As Saarland returned to Germany, the repercussions of the plebiscite were felt across international relations and shaped subsequent geopolitical narratives.