During the First World War, the three partitioned areas of Poland were pitted against each other as Russia was on the side of Britain and France as they fought against Germany and Austria-Hungary.

Poland is reverting to using its historical name for Kaliningrad, the Russian city and administrative region that sits on its border. From now on, it will be designated on Polish maps as Krolewiec ...

Independent Poland disappears from the map of Europe. ... 1939 - Nazi Germany invades Poland. Beginning of World War Two as the United Kingdom and France declare war on Germany in response.