The Free City of Danzig (comprising the city of Danzig and the surrounding territory, located between Germany and Poland) was established as a consequence of WWI in 1920. With the Treaty of Versailles it was separated from Germany, created as a separate state under protection of the League of Nations with special rights reserved to Poland. The Free City of Danzig had an ethnic German majority of over 90% and a Polish minority of about 4 to 8%. It had its own currency, flag, anthem, constitution, parliament and government.
The third verse of the anthem, speaking of the German connection to Danzig, was not sung by the Polish population.
On September 2, 1939, the day after the invasion of Poland, the Free City’s Nazi government voted to be annexed by Nazi Germany. After WWII, Danzig was ceded to Poland, the German residents were expelled, and the city was renamed Gdansk.
Special thanks to: Ben Cahoon and Bert Delahoussaye for some of this information and Paweł Ciupak for the sheet music and additional information.