West Prussia definition of West Prussia in the Free Online Encyclopedia.

West Prussia, Ger. Westpreussen, former province of Prussia, 9,867 sq mi (25,556 sq km), NE Germany, extending S from the Baltic Sea, between Pomerania on the west and East Prussia on the east. Danzig was the capital. The larger part of the region belonged to Poland until the Polish partitions of 1772 and 1793 and included Pomerelia (Ger. Pommerellen; see Pomerania Pomerania (pŏm'ərā`nēə)
..... Click the link for more information. ). The province also included, prior to World War I, the western portion of originally East Prussian territory, including the cities of Elbing, Marienburg, and Marienwerder. The Treaty of Versailles (1919) gave most of West Prussia to Poland (see Polish Corridor Polish Corridor, strip of German territory awarded to newly independent Poland by the Treaty of Versailles in 1919. The strip, 20 to 70 mi (32–112 km) wide, gave Poland access to the Baltic Sea.
..... Click the link for more information. ) and made Danzig and its environs a free city. The remainder of West Prussia was divided between the Prussian province of Grenzmark Posen-West Prussia and the district of West Prussia, incorporated with the province of East Prussia. The whole territory was again annexed to Germany at the outbreak (1939) of World War II, but in 1945 the Potsdam Conference placed it under Polish administration, where it has remained since.

West Prussia

a former province of NE Prussia, on the Baltic: assigned to Poland in 1945