Created from lands lost by Poland during its First Partition (1772), it included the former Polish province of Royal Prussia, except for Warmia, which was included in East Prussia.
In 1793, during the Second Partition of Poland, the city of Gdansk (Danzig) was incorporated into West Prussia. West and East Prussia were combined as a single province in 1824-78. Most of West Prussia returned to Poland in 1919, and both the eastern remainder (which in the meanwhile was joined to the Prussian province of East Prussia), and the western remainder (which in the meanwhile formed Grenzmark Posen-West Prussia) in 1945.
See also: Pomerania, Eastern Pomerania, Pomeranian Voivodship
Compare: East Prussia