The Belgian occupation of Eupen and Malmédy
The Treaty of Versailles of April 28, 1918, stipulated, among other things, that the cantons of Eupen, Malmédy, and Sankt-Vith were to be ceded to Belgium as of January 1, 1920. The cantons had little in common. Eupen and Sankt-Vith were primarily German-speaking, while Malmédy predominantly used the French language.
On July 25, 1940, the German postal service at the time issued two stamps commemorating the return of the territories of Eupen, Malmédy, and Moresnet to the German Empire. Eupen had old ties to Austria (the House of Habsburg) and the German Empire, while Malmédy had historical ties to Luxembourg. The territories were ceded to Prussia in 1815 during the Congress of Vienna, later becoming part of the German Empire.
Because Eupen and Malmédy had been German, the population, shops, and businesses possessed only German currency, Pfennig and Mark. Therefore, upon the transition to Belgium, a series of stamps bearing an overprint in German denominations was issued. From January 15, 1920, the Belgian postal service was responsible for the post offices in Eupen, Malmédy, and Sankt-Vith. The series of stamps was available from that date. The population of both areas was given the opportunity to cast a vote regarding their own future: to remain part of Belgium or to return to Germany. The vote was held between January 26, 1920, and July 23, 1920. People who did not wish to belong to Belgium could make this known at the respective town halls. However, they did not have much choice. Rumors circulated that those who did not wish to remain part of Belgium would lose all their rights and be deported to Germany. Consequently, only 271 people voted for return to Germany, even though 33.726 valid votes had been cast.
Fifty years later, on December 12, 1970, the Belgian Post issued a stamp commemorating the 'annexation' of the cantons of Eupen, Malmédy, and Sankt-Vith…. The validity of the stamps in Pfennigs and Marks for franking mail was short-lived. For they became invalid in Malmédy as early as March 13, 1920, and in Eupen on March 28, 1920. The series of stamps was quickly followed by a new series with overprints, separate for Eupen and separate for Malmédy. This is described in a later post on this blog.

Eupen belonged to Limburg until the French period, and the local dialect closely resembles Limburgish.