death of Duke Bolesław III, Poland was fragmented into several semi-independent principalities. The Samborides, principes in Pomerelia, gradually evolved into independent dukes, who ruled the duchy until 1294. Before Pomerelia regained independence in 1227, their dukes were vassals of Poland and Denmark. Since 1308-1309, following succession wars between Poland and Brandenburg, Pomerelia was subjugated by the Monastic state of the Teutonic Knights in Prussia. In 1466, with the second Peace of Thorn, Pomerelia became part of the Polish–Lithuanian Commonwealth as a part of autonomous Royal Prussia. After the First Partition of Poland in 1772 it was annexed by the Kingdom of Prussia and named West Prussia, and became a constituent part of the new German Empire in 1871. Thus the Polish Corridor was not an entirely new creation: the territory assigned to Poland had been an integral part of Poland prior to 1772, but with a large degree of autonomy. Historical population Perhaps the earliest census data on ethnic or national structure of West Prussia (including areas which later became the Polish Corridor) is from 1819. Karl Andree, "Polen: in geographischer, geschichtlicher und culturhistorischer Hinsicht" (Leipzig 1831), gives the total population of West Prussia as 700,000 inhabitants - including 50% Poles (350,000), 47% Germans (330,000) and 3% Jews (20,000). Data from the 19th century and early 20th century show the following ethnic changes in four "core" counties of the Corridor (Puck, Wejherowo - directly at the Baltic Sea coast - and Kartuzy, Kościerzyna - between Provinz Pommern and Free City Danzig): Allied plans for a corridor after World War I During the First World War, both sides made bids for Polish support, and in turn Polish leaders were active in soliciting support from both sides. Roman Dmowski, a former deputy in the Russian State Duma and the leader of the Endecja movement was especially active in seeking support from the Allies. Dmowski argued that an independent Poland needed access to the sea on demographic, historical and economic grounds as he maintained that a Poland without access to the sea could never be truly independent. After the war Poland was to be re-established as an independent state. Since a Polish state had not existed since the Congress of Vienna, the future republic's territory had to be defined. Giving Poland access to the sea was one of the guarantees proposed by United States President Woodrow Wilson in his Fourteen Points of January