The Province of West Prussia (German: Provinz Westpreußen; Kashubian: Zôpadné Prësë; Polish: Prusy Zachodnie) was a province of Prussia from 1773 to 1829 and 1878 to 1920. West Prussia was established as a province of the Kingdom of Prussia in 1773, formed from Royal Prussia of the Polish–Lithuanian Commonwealth annexed in the First Partition of Poland. West Prussia was dissolved in 1829 and merged with East Prussia to form the Province of Prussia, but was re-established in 1878 when the merger was reversed and became part of the German Empire. From 1918, West Prussia was a province of the Free State of Prussia within Weimar Germany, losing most of its territory to the Second Polish Republic and the Free City of Danzig in the Treaty of Versailles. West Prussia was dissolved in 1920, and it