On July 11, 1920, following the Paris Peace Conference, the “plebiscite areas” of East Prussia almost unanimously voted to remain part of Germany instead of joining the newly formed Polish Republic.
After more than a century of Partitions between the Russian Empire, the Kingdom of Prussia and the Habsburg Monarchy, Poland regained its independence at the end of World War I when the three partitioning powers were fatally weakened by war and revolutions. But until the Paris Peace Conference formally established Poland as a sovereign state, many territorial issues remained unresolved.
Poland’s post-war territorial issues
As a result, fighting for the borders of the reborn state dragged on even after the armistice was signed in November 1918.
The Polish-Ukrainian War expanded the Polish republic’s territory to include Volhynia and parts of Galicia, while at the same time Poznań was severed by the Greater Poland uprising, which succeeded in attaching most of the province’s territory to Poland by January 1919.
At the Paris Peace Conference, the Polish delegation, supported by the French, also made a number of demands in relation to the East Prussian regions of Allenstein and Marienwerder. But despite their protests, US President Woodrow Wilson and the other allies decided that plebiscites for self-determination should be held in these areas.
Indeed, while the regions concerned had changed hands at various times over the centuries between the Old Prussians, the Teutonic Knights, the Duchy of Prussia, Germany and Poland, many inhabitants of that region had Polish roots, were influenced by Polish culture and were classified as ethnic Poles.
The so-called “plebiscite areas” were placed under the authority of two Inter-Allied Commissions of five members, who were appointed by the Principal Allied and Associated Powers representing the League of Nations. The civil and municipal administration was continued by the existing German authorities, which were responsible to the Commissions for their duration.
A real plebiscite?
Both sides started propaganda campaigns, with pro-German campaigners protesting against the planned cession and Polish activists trying to convince ethnic Poles to liberate themselves from Prussian rule after a long period of Germanisation.
But pro-Polish activists decides to boycott the preparations to protest unequal treatment, which allowed German officials to falsify lists with eligible voters, writing down names of dead people or people who weren’t eligible to vote.
According to several sources, the German side also engaged in mass persecution of Polish activists in order to influence the vote, exerting strong psychological pressure on ethnic Poles to vote for Germany.
It is also believed the outcome of the vote was heavily influenced by the ongoing Polish-Bolshevik War which led many ethnic Poles in the region to vote for Germany out of fear that if the area was allocated to Poland it would soon fall under Soviet rule.
As a result, the vast majority of voters selected East Prussia over Poland (97% in the Allenstein region and 92% in the Marienwerder region), and most of the territories in question remained in Prussia, and therefore, in Germany.
The areas were eventually incorporated into Poland in 1945 as part of the so-called Recovered Territories before being swiftly overrun by the Red Army the following winter. They are today part of a single administrative province: the Warmian-Masurian Voivodeship.
Find out more about Central European history in our On this Day series.
Kafkadesk 
On July 11, 1920, following the Paris Peace Conference, the “plebiscite areas” of East Prussia almost unanimously voted to remain part of Germany instead of joining the newly formed Polish Republic.
After more than a century of Partitions between the Russian Empire, the Kingdom of Prussia and the Habsburg Monarchy, Poland regained its independence at the end of World War I when the three partitioning powers were fatally weakened by war and revolutions. But until the Paris Peace Conference formally established Poland as a sovereign state, many territorial issues remained unresolved.
Poland’s post-war territorial issues
As a result, fighting for the borders of the reborn state dragged on even after the armistice was signed in November 1918.
The Polish-Ukrainian War expanded the Polish republic’s territory to include Volhynia and parts of Galicia, while at the same time Poznań was severed by the Greater Poland uprising, which succeeded in attaching most of the province’s territory to Poland by January 1919.
At the Paris Peace Conference, the Polish delegation, supported by the French, also made a number of demands in relation to the East Prussian regions of Allenstein and Marienwerder. But despite their protests, US President Woodrow Wilson and the other allies decided that plebiscites for self-determination should be held in these areas.
Indeed, while the regions concerned had changed hands at various times over the centuries between the Old Prussians, the Teutonic Knights, the Duchy of Prussia, Germany and Poland, many inhabitants of that region had Polish roots, were influenced by Polish culture and were classified as ethnic Poles.
The so-called “plebiscite areas” were placed under the authority of two Inter-Allied Commissions of five members, who were appointed by the Principal Allied and Associated Powers representing the League of Nations. The civil and municipal administration was continued by the existing German authorities, which were responsible to the Commissions for their duration.
A real plebiscite?
Both sides started propaganda campaigns, with pro-German campaigners protesting against the planned cession and Polish activists trying to convince ethnic Poles to liberate themselves from Prussian rule after a long period of Germanisation.
But pro-Polish activists decides to boycott the preparations to protest unequal treatment, which allowed German officials to falsify lists with eligible voters, writing down names of dead people or people who weren’t eligible to vote.
According to several sources, the German side also engaged in mass persecution of Polish activists in order to influence the vote, exerting strong psychological pressure on ethnic Poles to vote for Germany.
It is also believed the outcome of the vote was heavily influenced by the ongoing Polish-Bolshevik War which led many ethnic Poles in the region to vote for Germany out of fear that if the area was allocated to Poland it would soon fall under Soviet rule.
As a result, the vast majority of voters selected East Prussia over Poland (97% in the Allenstein region and 92% in the Marienwerder region), and most of the territories in question remained in Prussia, and therefore, in Germany.
The areas were eventually incorporated into Poland in 1945 as part of the so-called Recovered Territories before being swiftly overrun by the Red Army the following winter. They are today part of a single administrative province: the Warmian-Masurian Voivodeship.
Find out more about Central European history in our On this Day series.