West Prussia

The Province of West Prussia (German: Provinz Westpreußen; Kashubian: Zôpadné Prësë; Polish: Prusy Zachodnie) was a province of Prussia from 1773 to 1829 and from 1878 to 1919. West Prussia was established as a province of the Kingdom of Prussia in 1773, formed from Royal Prussia following its annexation in the First Partition of Poland. West Prussia was merged with East Prussia in 1829 to form the Province of Prussia, then re-established in 1878 when the merger was reversed under the German Empire. West Prussia was a province of the Free State of Prussia within Weimar Germany in 1918–1919, but it lost most of its territory to the Second Polish Republic and the Free City of Danzig under the Treaty of Versailles. It was therefore dissolved in 1919, with its remaining western territory merging with Posen to form the Prussian Province Posen–West Prussia. Its eastern territory became part of East Prussia as the Region of West Prussia.

West Prussia's provincial capital alternated between Marienwerder (present-day Kwidzyn, Poland) and Danzig (Gdańsk, Poland). It was notable for its ethnic and religious diversity due to immigration and cultural changes. In the early Middle Ages, the bulk of the region was inhabited by West Slavic Lechitic tribes, but the Teutonic Order's conquest of the region in the 14th century resulted in extensive German colonisation. As a result of Germanisation, Germans became the most numerous ethnic group in West Prussia by the middle of the 19th century, although their distribution was uneven. Poles and Kashubians made around 36% of the population of the province. The majority of Germans were Protestant, while most Poles were Catholic. There was also a significant Jewish minority.