The border between Soviet Russia and Poland established by the Paris Peace Conference on 8 December 1919, and later named after the British Foreign Secretary Curzon. According to the principle of national self‐determination, it incorporated into Poland all those areas with a Polish majority. The Poles demanded a border further to the east, to include areas that had been Polish until the Polish partitions of the eighteenth century. This caused the Russo‐Polish War, as a result of which, in the Peace of Riga (18 March 1921), they secured a border much further to the east, enlarging their territory by about one‐third. Following the Hitler–Stalin Pact, Poland was divided between the USSR and Germany in September 1939 roughly along the Curzon Line, and it became the basis for Poland's eastern border after 1945.
Subjects: Contemporary History (Post 1945).