The Free City of Danzig is established.

The Free City of Danzig was a city-state under the protection and oversight of the League of Nations between 1920 and 1939, consisting of the Baltic Sea port of Danzig and nearly 200 other small localities in the surrounding areas. The polity was created on 15 November 1920 in accordance with the terms of Article 100 of the 1919 Treaty of Versailles after the end of World War I.