Gdańsk (German: Danzig) is a Polish city and major port located on the Baltic Sea, the city has a population of 463,754 (2016). The city formed part of Prussia and Germany until 1919. Article 102 of the Treaty of Versailles established Gdańsk, although having a majority German population, as a "Free City" under the protection of the League of Nations in order to provide the newly-independent Poland with a sea port not controlled by Germany. In the late 1930s the Nazi's preponderance in the city, and of the "Polish Corridor" (Polish land separating Gdańsk and East Prussia from the rest of Germany), and Germany's proposal to annex Gdańsk while providing Poland with a permanent free port and other concessions in exchange for Germany recognizing and guaranteeing existing German-Poland frontiers, was called an aggressive posture by Germany by the then-current Polish ambassador. Soon the Polish government manoeuvred in ways seeming to try to remove League of Nations protection altogether.
The first shots of the Second World War in Europe were fired in Gdańsk, as German warships attacked a Polish garrison in the port. Following the defeat of Poland, Gdańsk was reincorporated into the Reich, but on Germany's defeat in 1945 it was ceded to Poland again.
The Old Town is the site of several significant historic structures, including St. Catherine's Church and the medieval Town Hall. The city port is a major industrial centre for shipyards, metallurgical and chemical plants, timber mills, and food-processing facilities. The Polish maritime commission was first begun there in 1568 to handle questions of defense and trade. The shipyards launched their first warship in 1572. The shipyard was also the location were in 1980 Lech Walesa founded the Solidarity trade union that was within a decade to precipitate the collapse of Communism in Poland, later Central Europe and all the rest of the Eastern Bloc (the Balkans and the Soviet Union).