Free City of Danzig

State · 1809–1939 CE · at its largest around 1920 CE

The Baltic port of Danzig (Gdańsk) as a semi-autonomous city-state, first under Napoleonic protection and later under the League of Nations after the First World War.

On its lands while it lasted

Königsberg (1255–1945 CE): Capital of Duchy of Prussia (1526–1618), Brandenburg-Prussia (1619–1701).
Invasion of Poland (1939 CE): Germany invaded Poland on 1 September 1939, with the first shots fired at Westerplatte near Danzig, starting World War II in Europe. The Soviet Union invaded from the east on 17 September.