The Polish Corridor (also known as the Gdansk Corridor or Vistula Corridor, Polish Korytarz Polski) was a former Prussian strip of land between Pomerania (or Pomerellen) in the west and the lower course of the Vistula in the east. Germany had to cede it to Poland after the First World War. It separated East Prussia from the rest of Germany from 1920 until Poland’s invasion by the Nazis in September 1939. The corridor was not a political-historical unit; between the coastal section assigned to Poland and the German-Russian border of 1914, there was not only most of the former province of West Prussia but also parts of the historical Greater Poland that had belonged to the province of Posen. The western strips of Poznan and West Prussia remaining with the German Reich were united to form the province Grenzmark Posen-West Prussia.
After the Second Peace of Thorn in 1466, the area politically belonged to the Polish Crown as Prussia of the Royal Share of Poland-Lithuania until the First Partition of Poland-Lithuania in 1772 and to the Second Polish Republic as the Voivodeship of Pomerania from 1920 to 1939. Polish Corridor
The formation of the “Polish Corridor,” which geographically was a “dissecting corridor” through the German Reich, was part of the 14-point program of North American President Woodrow Wilson during the negotiations for the Versailles Peace Treaty. The democratically elected German delegates were not permitted to participate in these negotiations; they were forced to sign the treaty under considerable foreign policy pressure. Poland’s takeover of the territories took place when the treaty came into force on January 20, 1920. In the Treaty of Versailles, it was agreed that Poland must ensure unimpeded rail, ship, postal, telephone, and telegraph traffic through the corridor.
On July 11, 1920, the Corridor territories were ceded to the Second Polish Republic and formed the Pomeranian Voivodeship. In addition to Graudenz and Thorn (seat of the voivode), this included fourteen counties. The Cession area also included the Baltic Sea coast from the Piasnitz River to the Hela Peninsula, the Putziger Wiek to Sopot (the latter already belonged to the Free City of Gdansk). After Polish plans to integrate the port city of Danzig completely into Poland could not be realized, and it remained a “Free City,” only partially under Polish control, Poland began building its own port in the recreational and fishing town of Gdynia, which had only about 1300 inhabitants in 1921. Gdynia was expanded by the Polish state according to plan to become one of the largest trade, emigration, war, and fishing ports on the Baltic Sea with more than 112,000 inhabitants (1937) and was connected by a railroad line across the corridor to the industrial area in the likewise separated Polish part of Upper Silesia around Katowice (Katowice). In this way, it became independent of the connection through the territory of the Free City of Gdansk, which could be struck by German railwaymen at any time. Built for the export of Upper Silesian coal, this railroad line was also called the Coal Magistrale. The only seaport on Polish territory at that time also included military installations.
The competition between Gdansk and Gdynia led to disputes, which were exacerbated by the German-Polish trade war. The Gdansk side argued that after constructing Gdynia’s port, Poland no longer needed Gdansk as a port. In August 1933, Gdansk and Poland concluded a first agreement that guaranteed both ports an equal share of Polish maritime trade.
The Passport Polish Corridor
A Weimar Republik type issued to Frieda Prang, age 19, at the German consulate in Thorn (Pommerellen) on 10 Feb 1927. She went several times to Poland via Grudziadz. Surely a very unusual and for the German history significant place of issue.