Curzon Line
The Curzon Line was a proposed demarcation line between the Second Polish Republic and the Soviet Union, two new states emerging after World War I. Based on a suggestion by Herbert James Paton, it was first proposed in 1919 by Lord Curzon, the British Foreign Secretary, to the Supreme War Council as a diplomatic basis for a future border agreement. The line became a major geopolitical factor during World War II, when the USSR invaded eastern Poland, resulting in the split of Poland's territory between the USSR and Nazi Germany roughly along the Curzon Line in accordance with final rounds of secret negotiations surrounding the Molotov–Ribbentrop Pact.