Eupen-Malmedy became part of Belgium in the aftermath of World War I. The region, which had formerly been part of Prussia and the German Empire, was allocated to Belgium by the Treaty of Versailles. It was formally annexed after a controversial referendum in 1920, becoming part of Liège Province in 1925. Agitation by German nationalists during the interwar period led to its re-annexation by Nazi Germany during World War II. It was returned to Belgium in 1945. Today, it forms a large component of the German-speaking Community of Belgium, one of Belgium's three federal communities.