West Prussia was notable for its ethnic and religious diversity due to immigration and cultural changes, with the population becoming mixed over the centuries.

This region of the province was characterized by the Baltic Uplands, with southward flowing rivers joining the Noteć (German: Netze).

In the north was the Baltic coast, consisting of a graded shoreline with landmarks such as the Hel Peninsula stretching 35 kilometers into the Gdańsk Bay, and the Vistula Fens where that river meets the sea.

The region of Pomerelia or Gdańsk Pomerania, historically Polish and never inhabited by Old Prussians, was forcibly occupied by the monastic state of the Teutonic Knights in 1308, following an invasion of Poland under the pretext of helping the King Władysław I Łokietek to quell a rebellion, with subsequent Teutonic atrocities against the Polish population, such as the Slaughter of Gdańsk.

The possession of Danzig and Pomerelia by the Teutonic Order was questioned consistently by the Polish kings Władysław I and Casimir the Great in legal suits in the papal court in 1320 and 1333.

Subsequent rebellions organized by the local population against the Teutonic state, initially by the Lizard Union and later by the Prussian Confederation, both pledging allegiance to the Polish king, caused the Thirteen Years' War which ultimately led to the Second Peace of Thorn, when most of the region and was reclaimed by Poland and henceforth formed Royal Prussia, consisting of the originally Polish Pomerelia and Chełmno Land, expanded by the addition of parts of the formerly Old Prussian territories of Pomesania, Pogesania and Warmia.

The region had initially a degree of autonomy with an own local legislature, the Prussian Estates, and maintaining its own laws, customs and rights, but was ultimately re-absorbed directly into the Crown of the Kingdom of Poland, following the Union of Lublin in 1569.

The locally spoken language differed among social classes, with the aristocracy and urban burghers initially highly Germanised as a result of earlier Teutonic policies, but gradually Polonized in the later years, while the peasantry continued as predominantly Kashubian- and Polish-speaking.

East Prussia around Königsberg, on the other hand, remained with the State of the Teutonic Knights, who were reduced to vassals of the Polish kings.

The Hohenzollern rulers of Brandenburg-Prussia were able to remove the Polish suzerainty by the 1657 Treaty of Wehlau, taking advantage of the Russo-Swedish Deluge, shortly thereafter transforming their possessions into a kingdom.

Even though some German authors viewed the establishment of West Prussia as a historic reunification of the lands of the Teutonic State, officially, the Prussian government shunned from justifying the annexation by such argument.

The Partition Sejm ratified the cession on 30 September 1773, complemented by renouncement by the Polish king of his royal title in regard to Prussia.

[5] He had nothing but contempt for the szlachta, the numerous Polish nobility, and wrote that Poland had "the worst government in Europe with the exception of Ottoman Empire".

[6] In a letter to his brother Henry, Frederick wrote about the province that "it is a very good and advantageous acquisition, both from a financial and a political point of view.

After the final defeat of Napoleon in 1815, Danzig, Kulm, and Thorn were returned to West Prussia by resolution of the Vienna Congress.

Some of the areas of Greater Poland annexed in 1772 that had formed the Netze District were added to West Prussia as well (the remainder became part of the Grand Duchy of Posen).

According to Polish authors the real share of Poles and Kashubians was 43% (rather than 35.5% as in official figures), but many of them were counted as Catholic Germans by Prussian census clerks.

[21] As in all other areas, Poles and Jews were classified as "Untermenschen" by the German state, with their fate being slavery and extermination, the latter in particular during Intelligenzaktion Pommern, as well as in the Stutthof concentration camp.

Many German civilians were deported to labor camps like Vorkuta in the Soviet Union, where a large number of them perished or were later reported missing.

[22]Karl Andree, "Polen: in geographischer, geschichtlicher und culturhistorischer Hinsicht" (Leipzig 1831), gives the total population of West Prussia as 700,000 – including 50% Poles (350,000), 47% Germans (330,000) and 3% Jews (20,000).