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— CH. 1 · ORIGINS AND PROPOSALS —

Curzon Line

~4 min read · Ch. 1 of 6
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  • In December 1919, the Supreme War Council published a map and description of a new border line. Lord Curzon, the British Foreign Secretary, had proposed this demarcation to define Poland's eastern frontier after World War I. The Commission on Polish Affairs created the suggestion based on spoken language majorities within the former Russian Empire territories. This diplomatic basis aimed to separate areas with Polish populations from those inhabited by Ukrainians, Belarusians, Jews, and Lithuanians. The Allies forwarded it as an armistice line during subsequent conflicts between Poland and Soviet Russia. Both sides ignored the proposal when military situations favored their own territorial claims.

  • Polish forces pushed eastward in May 1920, taking Kiev before a strong Soviet counteroffensive forced Prime Minister Władysław Grabski to seek Allied assistance. Under pressure, he agreed to withdraw Polish troops to the 1919 version of the line near Galicia. On the 23rd of July 1920, Curzon signed a telegram proposing that a ceasefire be established along the line. The Soviets responded to the note with refusal on July 17, commenting on delayed British interest in peace negotiations. During August, the Soviets were defeated by Poles just outside Warsaw, leading to a Polish offensive. The Polish government then repudiated Grabski's agreement regarding the line because the Allies had not delivered support or protection. At the March 1921 Treaty of Riga, the Soviets conceded a frontier well to the east of the Curzon Line. This treaty provided Poland with almost 200,000 square kilometers of land, averaging about 480 kilometers east of the proposed boundary. The Polish-Soviet border was recognized by the League of Nations in 1923 and confirmed through various agreements.

  • The Molotov, Ribbentrop Pact of August 1939 provided for partitioning Poland along rivers including the San, Vistula, and Narew. These boundaries did not follow the Curzon Line but reached far beyond it, awarding the Soviet Union territories of Lublin and areas near Warsaw. In September, after Poland's military defeat, the Soviet Union annexed all territories east of the Curzon Line plus Białystok and Eastern Galicia. Hundreds of thousands of Poles and fewer Jews were deported eastwards into the Soviet Union following falsified referendums. During July 1941, Nazi Germany seized these territories during Operation Barbarossa. Most of the Jewish population was deported or killed by German forces during occupation. In 1944, Soviet armed forces recaptured eastern Poland from the Germans. The Soviets unilaterally declared a new frontier approximately matching the Curzon Line. The Polish government-in-exile in London bitterly opposed this change, insisting on maintaining the Riga line instead.

  • During conferences between Stalin and western Allies at Tehran and Yalta, leaders Roosevelt and Churchill asked Stalin to reconsider border arrangements, particularly over Lwów. Stalin refused to alter the proposed boundary despite Allied pressure. At Yalta negotiations, Stalin posed the question: Do you want me to tell the Russian people that I am less Russian than Lord Curzon? The altered Curzon Line thus became the permanent eastern border of Poland. Western Allies recognized this arrangement in July 1945. The border received some adjustments later, with the biggest revision occurring in 1951. When the Soviet Union ceased to exist in 1991, the Curzon Line became Poland's eastern border with Lithuania, Belarus, and Ukraine. Franklin Roosevelt, Winston Churchill, and Joseph Stalin issued statements affirming use of the line with five-to-eight-kilometer variations as the official eastern border.

  • A 1944 article in The Times estimated that in 1931 between 2.2 and 2.5 million Poles lived east of the Curzon Line. Historian Yohanan Cohen calculated that in 1939, total population reached 12 million across territories gained via Treaty of Riga. This included over 5 million Ukrainians, between 3.5 and 4 million Poles, 1.5 million Belarusians, and 1.3 million Jews. Ukrainian and Belarusian populations combined formed majority status within interwar Eastern Poland. Significant Jewish inhabitants also resided throughout these areas. Poles constituted majorities in main cities like Lwów, Wilno, Grodno, and Stanisławów alongside Jewish communities. Rural areas showed mixed ethnic patterns according to census data from 1931. Cities such as Vilnius District Municipality and Sapotskin region maintained Polish majorities even after World War II. About 3 million Roman Catholic Poles lived east of the Curzon Line before expulsion operations began.

  • Despite mass expulsions of most ethnic Poles from Soviet Union between 1944 and 1958, the 1959 Soviet census still counted around 1.4 million ethnic Poles remaining. The Byelorussian SSR held 538,881 Poles while Ukrainian SSR contained 363,297. Lithuanian SSR had 230,107 Poles with smaller numbers in Latvia, Estonia, and rest of USSR totaling 1,380,282. According to more recent census data, about 295,000 Poles existed in Belarus by 2009 representing 3.1% of total population. About 2.1 to 2.2 million people died, fled, emigrated or were expelled to newly annexed German territories following World War II. Ukrainian nationalists continued partisan warfare against Soviets, being imprisoned and sent to Gulag camps where they participated in uprisings like Kengir, Norilsk, and Vorkuta. Much of Ukrainian population was forcibly resettled after World War II to Soviet Ukraine through Operation Vistula.

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Foreign relations of the Soviet Union

Common questions

Who proposed the Curzon Line in December 1919?

Lord Curzon, the British Foreign Secretary, proposed the demarcation to define Poland's eastern frontier after World War I. The Commission on Polish Affairs created the suggestion based on spoken language majorities within the former Russian Empire territories.

When did the Treaty of Riga establish a border east of the Curzon Line?

The March 1921 Treaty of Riga established a frontier well to the east of the Curzon Line. This treaty provided Poland with almost 200,000 square kilometers of land averaging about 480 kilometers east of the proposed boundary.

What happened to the Curzon Line during the Molotov Ribbentrop Pact of August 1939?

The Molotov Ribbentrop Pact of August 1939 provided for partitioning Poland along rivers including the San Vistula and Narew without following the Curzon Line. In September after Poland's military defeat the Soviet Union annexed all territories east of the Curzon Line plus Białystok and Eastern Galicia.

Why did Stalin refuse to alter the Curzon Line at Yalta negotiations in 1945?

Stalin refused to alter the proposed boundary despite Allied pressure because he posed the question Do you want me to tell the Russian people that I am less Russian than Lord Curzon. Western Allies recognized this arrangement in July 1945 making it the permanent eastern border of Poland.

How many Poles lived east of the Curzon Line according to 1931 census data?

A 1944 article in The Times estimated that between 2.2 and 2.5 million Poles lived east of the Curzon Line in 1931. About 3 million Roman Catholic Poles lived east of the Curzon Line before expulsion operations began.

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All sources

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