https://encyclopedia.ushmm.org/content/en/article/danzig
Danzig.
German City Danzig taken from Germany in 1919 after WW1.
Given free status and... put on north east of Poland. To punish
Germany. It included some 200 German villages and towns. Hitler's
desire to reunite Germany included taking Danzig back...by going
through Poland.
- They also claimed Poland fired first. Which was a lie.
A fascinating story in itself.
After World War II, Danzig and its environs became part of Poland. The German population either fled or was expelled. The Poles renamed the city Gdansk.
Actually, it is more of a polish city. The city was founded in 997 under polish rule and it stayed like that for first 300 years of its existance, to be then ruled by german teutonic order for next 150 years and come back to the polish crown for another 300 years. In fact in its whole over 1000 years history, the city was under polish rule for more than 700 years and under german one for less than 300.
The name thing is actually the other way round. The german word "Danzig" is simply the way germans written the original name of the city, which was "Gdańsk" ever since the city was founded.
A better choice would by the city of Königsberg (currently Kalinigrad or Калининград), which was also conquered by the teutons, but it was under german rule for much longer than Gdańsk was. It was also not founded by the germans, but from old prussians, indigenous people of the region who disappeared through the ages and who never had a chance to get it back under their rule.