Sejny Uprising

Sejny Uprising
Part of Polish–Lithuanian War

Lt. Adam Rudnicki, leader of the Sejny Uprising, and his colleagues. August 1919.
DateAugust 23 – September 7, 1919
Location
Result Polish victory
Territorial
changes
Lithuanians retreated behind the Foch Line; Poland secured Sejny
Belligerents
Second Polish Republic Polish Military Organization (PMO)
Second Polish Republic 41st Infantry Regiment
Lithuania Lithuanian Sejny Command
Lithuania 1st Reserve Battalion
Commanders and leaders
Second Polish Republic Adam Rudnicki
Second Polish Republic Mieczysław Mackiewicz
Second Polish Republic Wacław Zawadzki 
Lithuania Kazys Ladiga
Strength
900[1]–1,200[2] PMO volunteers
800 regular troops[3]
900 regular troops[3]
300 volunteers[4]
Casualties and losses
37 killed in action
70 wounded

The Sejny Uprising or Seinai Revolt (Polish: Powstanie sejneńskie, Lithuanian: Seinų sukilimas) refers to a Polish uprising against the Lithuanian authorities in August 1919 in the ethnically mixed area surrounding the town of Sejny (Lithuanian: Seinai). When German forces, which occupied the territory during World War I, retreated from the area in May 1919, they turned over administration to the Lithuanians. Trying to prevent an armed conflict between Poland and Lithuania, the Entente drew a demarcation line, known as the Foch Line. The line assigned much of the disputed Suwałki (Suvalkai) Region to Poland and required the Lithuanian Army to retreat. While the Lithuanians retreated from some areas, they refused to leave Sejny (Seinai), because of its major Lithuanian population.[5] Polish irregular forces began the uprising on August 23, 1919, and soon received support from the regular Polish Army. After several military skirmishes, Polish forces secured Sejny and the Lithuanians retreated behind the Foch Line.

The uprising did not solve the larger border conflict between Poland and Lithuania over the ethnically mixed Suwałki Region. Both sides complained about each other's repressive measures.[6] The conflict intensified in 1920, causing military skirmishes of the Polish–Lithuanian War. Sejny changed hands frequently until the Suwałki Agreement of October 1920, which left Sejny on the Polish side. The uprising undermined the plans of Polish leader Józef Piłsudski who was planning a coup d'état in Lithuania to replace the Lithuanian government with a pro-Polish cabinet which would agree to a union with Poland (the proposed Międzymorze federation). Because the Sejny Uprising had prompted the Lithuanian intelligence to intensify its investigations of Polish activities in Lithuania, they discovered plans for the coup and prevented it, arresting Polish sympathizers. These hostilities in Sejny further strained the Polish–Lithuanian relations.

Eventually, Poland and Lithuania reached an agreement on a new border that left Sejny on the Polish side of the border. The Polish–Lithuanian border in the Suwałki Region has remained the same since then (with the exception of the World War II period).

  1. ^ Cite error: The named reference BuchSt was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference Manc was invoked but never defined (see the help page).
  3. ^ a b Lesčius 2004, p. 276.
  4. ^ Lesčius 2004, p. 275.
  5. ^ Senn 1975, p. 158.
  6. ^ Cite error: The named reference BuchKr was invoked but never defined (see the help page).