What was the year of XXX's inception?
West Prussia
In February 1920, Germany (after it had been defeated in 1918) handed over West Prussia's mainly German populated central parts to become the so-called Polish Corridor (i.e. Pomeranian Voivodeship) and the Free City of Danzig, while the parts remaining with the German Weimar Republic became the new Posen-West Prussia or were joined to the Province of East Prussia as Regierungsbezirk West Prussia.