Curzon Line

The Curzon Line

Historical demarcation line of World War II

Lighter blue line: Curzon Line "B" as proposed in 1919. Darker blue line: "Curzon" Line "A" as proposed by the Soviet Union in 1940. Pink areas: Former pre-World War II provinces of Germany transferred to Poland after the war. Grey area: Pre-World War II Polish territory east of the Curzon Line annexed by the Soviet Union after the war.

The history of the Curzon Line, with minor variations, goes back to the period following World War I. It was drawn for the first time by the Supreme War Council as the demarcation line between the newly emerging states, the Second Polish Republic, and Bolshevik Russia. The proposal was put forward by British Foreign Secretary George Curzon, to serve as a diplomatic basis for the future border agreement, and in that form, it never materialized because the war went on.

The line became a major geopolitical factor during World War II, when Joseph Stalin invaded eastern Poland and split its territory along the Curzon Line with Adolf Hitler. The western powers entered into negotiations with the Soviet Union following Operation Barbarossa. Throughout the war until the Tehran Conference, the Allies did not agree that Poland's future eastern border should be kept at the same Curzon Line drawn in 1939; but Churchill's position changed after the Soviet victory at the Battle of Kursk.

Following a private agreement at the Tehran Conference, confirmed at the 1945 Yalta Conference, the Allied leaders Franklin Roosevelt, Winston Churchill, and Stalin issued a statement affirming the use of the Curzon Line, with some five-to-eight kilometre variations, as the eastern border between Poland and the Soviet Union. When Churchill proposed to add parts of East Galicia, including the city of Lwów, to Poland's territory (following Line B), Stalin argued that the Soviet Union could not demand less territory for itself than the British Government had reconfirmed previously several times. The Allied arrangement involved compensation for this loss via the incorporation of formerly German-held areas (the Recovered Territories) into Poland. As a result, the current border between the countries of Belarus, Ukraine and Poland is an approximation of the Curzon Line.