“Curzon Line” proposed by Lord George Curzon in 1919 as demarcation between Poland and RSFSR; later used to describe Ukrainian ethnic territories west of modern Polish-Ukrainian border (Zakerzonnya)
Executive summary
The Curzon Line was first proposed on 8 December 1919 as a provisional demarcation for Poland’s eastern frontier by the Allied Supreme Council and associated with British Foreign Secretary Lord Curzon; it was intended as an armistice/administrative line based largely on language/ethnicity considerations (Supreme Council) rather than a final legal border [1] [2] [3]. After World War II the USSR and the Allies used a variant of that 1919 line as the basis for Poland’s eastern border — a shift that left large Ukrainian-populated areas on the Soviet side (the territory sometimes called Zakerzonnya or “lands beyond the Curzon Line”) [1] [2] [4].
1. Origins: a Commission’s “temporary” line, not a permanent treaty boundary
The Curzon Line originated in Allied planning at the Paris peace conferences and was produced by the Supreme War Council / Commission on Polish Affairs as a recommended eastern limit for Poland on December 8, 1919; it was explicitly framed as a provisional demarcation tied to spoken-language majorities rather than as a final international boundary [1] [3] [5].
2. Lord Curzon’s role and the naming of the line
George Nathaniel Curzon, British foreign secretary (1919–24), lent his name to the proposal after his interventions in mid-1919 and July 1920; historians and reference works link the line to his proposals even though it evolved from Commission work and other maps considered by the Entente [1] [6] [7].
3. The line in the interwar wars and diplomacy
Poland and Soviet Russia did not accept the Entente plan in 1919–20; the Polish–Soviet War and the Peace of Riga (March 1921) produced a frontier well east of the Curzon Line because Poland’s armies had taken and retained territories further east [1] [2] [8]. Contemporary accounts and later analyses treat the Curzon Line as one of several competing demarcations in a chaotic post‑WWI diplomacy [7] [3].
4. WWII and postwar settlement: the Curzon Line becomes de facto border
During and after WWII strategic diplomacy — Tehran, Yalta and later agreements — led the Allies to accept the Curzon Line (with minor variations) as the practical eastern boundary of postwar Poland; the Soviet occupation of eastern Poland in 1939 and subsequent Soviet‑Polish treaties resulted in Poland’s eastern frontier moving roughly to the Curzon alignment [1] [2].
5. Ethnicity and Zakerzonnya: what the line meant on the ground
Sources describe the 1919 proposal as informed by “spoken language majority” calculations; later Soviet and Polish practice treated the Curzon-derived border as an ethnographic break in part — leaving significant Ukrainian, Belarusian and Polish communities split by the new frontier. Modern usages of the term Zakerzonnya (lands “beyond the border”) refer to Ukrainian-populated areas left on the Soviet side west of today’s Polish–Ukrainian border; reporting notes that the Soviet authorities and some Polish decisions identified these territories with the Curzon concept [1] [4].
6. Competing perspectives and political agendas
Histories stress competing agendas: the Entente framed the line as a minimal frontier and a concession to national self-determination; Poland viewed Curzon’s proposal as a ceasefire instrument rather than a final boundary and sought more territory in 1919–21; the USSR later treated the line as justification for annexations and for post‑1945 borders [3] [8] [1]. Secondary sources show that naming the line after Curzon can understate the Commission and League/Entente role and that wartime power politics — not just ethnography — determined the final border [7] [1].
7. What the available sources do not say
Available sources do not mention precise modern Ukrainian nationalist or local narratives about Zakerzonnya beyond noting the Soviet/Polish post‑1945 alignment to the Curzon concept; they do not provide detailed Polish‑ or Ukrainian‑language contemporary polemics about the name “Zakerzonnya” in these snippets (not found in current reporting).
8. Why this matters today
The Curzon Line illustrates how a provisional administrative map, drawn under political pressure and justified partly by “ethnographic” criteria, became enshrined through great‑power diplomacy and war. That transformation shows how legal niceties (a recommendation, a ceasefire line) are overtaken by force and bargaining — a pattern visible in the line’s 1919 origin and its 1945 implementation [1] [2] [3].
Limitations: this summary relies on the provided snippets and reference entries (encyclopedias, research articles and contemporary overviews) and does not draw on archival primary documents not included in the dataset; where specific local terms (like Zakerzonnya) are discussed, the current sources mainly link the concept to post‑1945 Soviet/Polish treatment of borders rather than to a single defining legal act [4] [1].