Allenstein was a district in East Prussia with a mixed German and Slavic population of more than 500,000. The French and the British were looking for ways to strengthen the new Polish republic as a bulwark against the Soviet threat. They both tried to attach Allenstein to Poland, but the Germans objected strongly, so a plebiscite was called. Although Allenstein had a sizable Slavic minority, these people were not Poles. They were Masurians who shared the Lutheran faith with the German-speaking Prussians. In the plebiscite, the Masurians voted with the Germans for a lopsided return of 97.9 percent in favor of union with Germany.
Allenstein was returned to Germany on August 20, 1920. After World War II, its German population was expelled and replaced with Poles taken from lands in eastern Poland annexed by the Soviet Union. Today, Allenstein is the Polish city of Olsztyn.



After the end of the First World War, the Treaty of Versailles placed municipalities of Eupen and Malmedy from 1920 to 1925 under Belgian administration, in the form of the Gouvernement Eupen-Malmedy. The region was eventually subject to a plebiscite to determine whether the region would be permanently separated from Germany and annexed to Belgium. However, the vote was not secret, since the ballots required the name and postal address of each voter. Fearing expulsion if they voted for Germany, the populations of Eupen and Malmedy voted to join Belgium.
A number of overprinted Belgium stamps were used there until 1925, when regular Belgian issues came into use.



Marienwerder was a district of West Prussia centered on the town of the same name, just east of the Vistula River. Had the policy of national self-determination been strictly followed, the new state of Poland would have been landlocked. Because a seaport and access to the Baltic Sea were considered economic necessities for the new state, the Allies awarded most of West Prussia and its sizeable German population to Poland. This strip of land, called the Polish Corridor, cut East Prussia off from the rest of Germany. Marienwerder in West Prussia had an overwhelmingly German population, and the Germans were able to secure a plebiscite for the area. The people voted overwhelming for Germany, and in July 1920 Marienwerder was returned to Germany.
After WWII, the German population was expelled and replaced by Poles from eastern Poland, and the city was renamed Kwidzyn.



Under the Treaty of Versailles after World War I, Memel and the surrounding Memel Territory (or Klaipeda Region) was made a protectorate of the Entente States, in order to guarantee port rights to Lithuania and Poland. The territory was administered by an autonomous government, under a French High Commissioner, with the ultimate intention that it would be a self-governing territory on the model of Danzig.
Lithuania made the decision to invade Memel and the Memel Territory in January 1923. Weapons for the Lithuanians were supplied by Germans. The German government, through intermediates, assured Lithuania that they would not interfere with the Lithuanian intervention in the region. The French garrison made only limited resistance efforts. As the Allies had no troops to spare for the restoration of their authority they consequently took refuge in negotiations which eventually left the juridical sovereignty in the hands of Lithuania.
Animosity between the local Memellanders and the occupying Lithuanians prevented the smooth working of the government. In 1934, 538 German employees were dismissed and 126 Germans were accused of treason before a Lithuanian Military tribunal, after about 1,100 weapons and other illegal materials were found in their possession. Before the election of September 1935, German newspapers were suppressed and four candidates were deprived of Lithuanian citizenship to prevent their election; some 9,000 'new' Lithuanians were given the right to vote.
Opposition by the population to Lithuanian rule continued. New elections were held on 11 December 1938. As the Lithuanian police had been withdrawn and public order had been entrusted to the native German auxiliary police, the elections displayed an overwhelming majority for the Germans, who then appealed to the German government. Nazi Germany delivered an ultimatum to the Lithuanian Foreign Minister on March 20, 1939, demanding the surrender of the Memel region to German control. Lithuania submitted to the ultimatum and, in exchange for the right to use the new harbour facilities as a Free Port, ceded the disputed region to Germany in the late evening of 22 March 1939.
After World War II, the area was reincorporated in the Lithuanian Soviet Socialist Republic.



Sections of the Rhineland bordering Belgium were annexed by the Treaty of Versailles by Belgium. Belgium stamps with overprint 'ALLEMAGNE DUITSCHLAND' were used there.



A coal-rich district in western Germany, southeast of Luxembourg. According to Treaty of Versailles the highly industrialized Saarland was to be governed by the League of Nations for a period of 15 years, and its coalfields ceded to France as part of the German war reparations. At the end of that time a plebiscite was to determine the Saar's future status. Saar had a currency, the Saar franc, and its own postage stamps during this period.
When the 15-year-term was over, a plebiscite was held in the territory on 13 January 1935: 90.3% of those voting wished to join Germany. On 17 January 1935, the territory's re-union with Germany was approved by the League Council.
The Saar was again occupied by France in 1945. To see stamps from that period click here.



Schleswig was a grand duchy with a mixed German and Danish population. Prussia had acquired Schleswig as a result of wars with Denmark in 1864 and Austria in 1866. After WWI, the Treaty of Versailles called for a plebiscite to decide the fate of the territory. For the plebiscite, Schleswig was divided into Zone 1 in the north and Zone 2 in the south (Central Schleswig). In Northern Schleswig 75% voted for reunification with Denmark and 25% for staying with Germany. In Central Schleswig the situation was reversed with 80% voting for Germany and 20% for Denmark. No vote ever took place in the southern third of Schleswig as the likely outcome was apparent. On 15 June 1920, Northern Schleswig was officially reunited with Denmark. Central Schleswig chose to remain with Southern Schleswig as part of Germany and is today a part of the German state of Schleswig-Holstein..



Upper Silesia (Gorny Slask in Polish), with a mixed Polish and German population, was part of Germany before WWI. From 1919-1921 three Silesian Uprisings occurred among the Polish-speaking populace of Upper Silesia, so Italy, France, Great Britain and the United States sent troops to occupy and pacify the area. The plebiscite, held on March 20, 1921, was indecisive. The vote was nearly equally divided between Poland and Germany, so the Inter-Allied Control Commission turned the question over to the Council of the League of Nations. On the basis of the reports of this commission and those of its experts, the Council awarded the greater part of the Upper Silesian industrial district to Poland. The eastern part, which was partially ethnic Polish, came under Polish rule as the Autonomous Silesian Voivodeship, while the mostly German-speaking western part remained part of Germany as the Province of Upper Silesia
Upper Silesia has been part of Poland since the end of WWII.



As a result of the Versailles treaty after World War I, Danzig (Gdansk) became a free city under the protection of the League of Nations. Its predominantly German population had no right of self-determination in a referendum as in other disputed parts of the former German Empire. When Poland regained its independence after World War I, the Poles hoped to regain the city to provide the free access to the sea which they had been promised by the Allies. However, since the population of the city was predominantly German, it was not placed under Polish sovereignty, but became the Free City of Danzig, an independent quasi-state under the auspices of the League of Nations, governed by its predominantly German residents but with its external affairs largely under Polish control. The Free City had its own constitution, national anthem, parliament and government. It issued its own stamps and currency.
The vast majority of the city's population favoured eventual return to Germany. In the early 1930s the Nazi Party capitalized on these pro-German sentiments, and in 1933 the Nazis achieved dominance in the city government. On September 1, 1939, Germany attacked Poland, triggering the outbreak of World War II. The city was annexed by Nazi Germany. After the WW2 Gdansk was assigned to Poland. The remaining German residents of the city who survived the war were expelled to the western zones of remaining Germany, and henceforth the city became wholly Polish populated.