The Czechoslovak-Polish War, also known mostly in Czech sources as the Seven-day war was a military confrontation between Czechoslovakia and Poland over the territory of Cieszyn Silesia in early 1919.

The Second Polish Republic, at the time officially known as the Republic of Poland, was a country in Central and Eastern Europe that existed between 7 October 1918 and 6 October 1939. The state was established in the final stage of World War I. The Second Republic ceased to exist in 1939, after Poland was invaded by Nazi Germany, the Soviet Union, and the Slovak Republic, marking the beginning of the European theatre of the Second World War. The Polish government-in-exile was established in Paris and later London after the fall of France in 1940.