The Ukrainian National Democratic Alliance, (UNDO) (Ukrainian: Українське національно-демократичне об'єднання, УНДО, Ukrayin'ske Natsional'no-Demokratichne Obyednannia, Polish: Ukraińskie Zjednoczenie Narodowo-Demokratyczne) was the largest Ukrainian political party in the Second Polish Republic, active in Western Ukraine. It dominated the mainstream political life of the Ukrainian minority in Poland, which with almost 14% of Poland's population was the largest minority within that country.
UNDO was founded in 1925 and dissolved during the Soviet annexation of western Ukraine in 1939. Throughout the interwar years, UNDO enjoyed both German and Soviet financial support in their struggle against Poland.
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