The city has a complex history, having had periods of Polish, German and self rule. An important shipbuilding and trade port since the Middle Ages, in 1361 it became a member of the Hanseatic League which influenced its economic, demographic and urban landscape. It also served as Poland's principal seaport, and was the largest city of Poland in the 15th-17th centuries. In 1793, within the Partitions of Poland, the city became part of Prussia, from 1920 to 1939 it was a Free City under the protection of the League of Nations.
