Lt. Adam Rudnicki, leader of the Sejny Uprising, and his colleagues. August 1919.
| Polish Military Organization (PMO)
41st Infantry Regiment
| Lithuanian Sejny Command
1st Reserve Battalion
|Commanders and leaders|
|900–1,200 PMO volunteers
800 regular troops
|900 regular troops
|Casualties and losses|
|37 killed in action
The Sejny Uprising or Seinai Revolt (Polish: Powstanie sejneńskie, Lithuanian: Seinų sukilimas) refers to a Polish uprising in the ethnically-mixed area surrounding the town of Sejny (Lithuanian: Seinai) against the Lithuanian authorities in August 1919. When German forces, which occupied the territory during World War I, retreated from the area, the administration was handed 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. 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 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. 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). The coup was discovered and stopped as the Sejny Uprising had prompted the Lithuanian intelligence to intensify its investigations of Polish activities in Lithuania. The 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).
During the ages, the lands surrounding the town of Suwałki had been variously part of Lithuanian, Polish, and German borderlands. Since 1569, during the era of the Polish–Lithuanian Commonwealth, the territory belonged to the Podlaskie Voivodeship and was part of the Kingdom of Poland rather than the Grand Duchy of Lithuania. However, Sejny was a property of Dominican friars from Vilnius. During the 19th century the town was part of Russian-controlled Congress Poland. During World War I the region was captured by the German Empire, which intended to incorporate the area into its province of East Prussia. After the German defeat, the victorious Entente was willing to assign the territory to either the newly-independent Poland or Lithuania. The future of the region was discussed at the Paris Peace Conference in January 1919. The Germans, whose former Ober-Ost administration was preparing to evacuate, initially supported leaving the area to a Polish administration. However, as Poland was becoming an ally of France, German support gradually shifted towards Lithuania. In July 1919, when the German troops began their slow retreat from the area, they delegated the administration to local Lithuanian authorities. Lithuanian officers and troops, who first arrived to the region in May, began to organize military units in the pre-war Sejny county.
According to Russian statistics of 1889, there were 57.8% of Lithuanians, 19.1% of Poles, and 3.5% of Belarusians in the Suwałki Governorate. It is generally agreed that Lithuanians formed majority in the northern Suwałki Governorate, while Poles concentrated in south. However, Lithuanian and Polish historians continued to disagree over the location of the line that separated the Lithuanian from the Polish majorities. Lithuanians claimed that Sejny and the surrounding area were inhabited primarily by Lithuanians, while the Poles claimed exactly the opposite. The German census of 1916 showed that 51% of Sejny population was Lithuanian.
 Demarcation lines
The Conference of Ambassadors drew the first demarcation line between Poland and Lithuania on June 18, 1919. The line satisfied no one and Polish troops continued to advance deeper into the Lithuanian-controlled territory. These attacks coincided with signing of the Treaty of Versailles on June 28 and eliminated danger from Germany. Attempting to halt further hostilities, Marshal of France Ferdinand Foch proposed a new line, known as the Foch Line, on July 18, 1919. The Foch Line was negotiated with Polish war mission, led by General Tadeusz Jordan-Rozwadowski in Paris, while Lithuanian representatives were not invited. Two major modification were made over the line of June 18: first, the entire line was moved west to give extra protection to the strategic Warsaw – Saint Petersburg Railway and second, the Suwałki Region, including towns of Sejny, Suwałki, Puńsk, was assigned to Poland. Despite assurances that the lines was just temporary measure to normalize the situation before full negotiations could take place, the southern Foch Line still stands as the border between Lithuania and Poland.
On July 26, the Foch Line was accepted by the Conference of Ambassadors as the provisional border between the two states. Lithuanians were informed about this decision only on August 3. Neither country was satisfied: both Lithuanian and Polish forces would have to retreat from the Suwałki and Vilnius Regions respectively. Germans, still present in the region, also objected to the line. The Lithuanian forces (about 350 strong) left the town of Suwałki by August 7, but stopped in Sejny and formed a line on the Czarna Hańcza river – Wigry Lake. Lithuanians believed that the Foch Line was not the final decision and that they had the duty to protect Lithuanian outposts in the region.
 Uprising preparations
On August 12, 1919, two days after the Germans retreated from Sejny a Polish meeting in Sejny attracted over 100 delegates from neighboring Polish communities; the meeting passed a resolution that "only securing the area by Polish Army can solve the problem." The Sejny branch of the Polish Military Organization (PMO), led by Polish regular army officers Adam Rudnicki and Wacław Zawadzki, began preparing for the uprising on August 16. PMO members and local militia volunteers numbered some 900 or 1,200 men (sources vary). The uprising was scheduled for the night of August 22 to 23, 1919. The date was chosen to coincide with the withdrawal of German troops from the town of Suwałki. The Poles hoped to capture the territory up to the Foch Line and move further to the towns of Seirijai, Lazdijai, Kapčiamiestis as far as Simnas.
According to the Polish historian Tadeusz Mańczuk, Piłsudski – who was planning a coup d'état in Kaunas – discouraged the local PMO activists from carrying out the Sejny Uprising. Piłsudski reasoned that any hostilities could leave Lithuanians even more opposed to the proposed union with Poland (see Międzymorze). The local PMO disregarded his recommendations and launched the uprising which, while locally successful, led to the failure of the nationwide coup.
On August 17, a Lithuanian counter-demonstration was staged, whose participants read a recently issued recruitment proclamation of Lithuanian volunteer army: "Citizens! Our nation is in danger! To arms! We shall leave not a single occupant on our lands!" On August 20, Prime Minister of Lithuania Mykolas Sleževičius visited Sejny and called on Lithuanians to defend their lands "to the end, however they can, with axes, pitchforks and scythes". According to Lesčius, at the same time the Lithuanian command in Sejny had only 260 infantry and 70 cavalry personnel, stretched along the long line of defense. There were only 10 Lithuanian guards and 20 clerical staff in the town itself. Mańczuk and Buchowski note that the Polish insurgents estimated the Lithuanian forces at 1,200 infantry (Mańczuk also adds an estimate of 120 cavalry), including a 400-strong garrison in Sejny.
 Military skirmishes
According to Lithuanian historian Lesčius, the first Polish assault of about 300 PMO members on August 22 was repelled, but the next day Lithuanians were forced to retreat towards Lazdijai. Over 100 Lithuanians were imprisoned in Sejny when their commander Bardauskas sided with the Poles. The Polish insurgents also attacked Lazdijai and Kapčiamiestis, towns on the Lithuanian side of the Foch Line. In early morning of August 25, Lithuanians counterattacked and recaptured Sejny. Polish sources claim that Lithuanians there were aided by a company of Germans volunteers, but Lithuanian sources assert that it was an excuse used by Rudnicki to explain his defeat. The Lithuanian forces recovered some important documents and property, freed Lithuanian prisoners and, according to Mańczuk, executed several of the PMO fighters they found wounded. On the evening of August 25, the first regular unit (41st Infantry Regiment) of the Polish army received an order to advance towards Sejny. The Lithuanian forces retreated on the same day when they learned about approaching Polish reinforcements. According to Mańczuk, they based their retreat on an erroneous report about a "large Polish cavalry unit" operating to their rear; in fact only small groups of Polish partisans operated there. Later the next day, during the afternoon of August 26, the PMO forces in Sejny were joined by the 41st Infantry Regiment.
On August 26, a large anti-Polish protest took place in Lazdijai, demanding to march on Sejny. The last Lithuanian attempt to retake the town was made on August 28. The Lithuanians (about 650 men) were defeated by the combined forces of the Polish Army (800 men) and PMO volunteers (500 men). On August 27, the Poles officially demanded that Lithuanians retreat behind the Foch Line. On September 1, Rudnicki announced incorporation of PMO volunteers into the 41st Infantry Regiment. During the negotiations on September 5, it was agreed to settle on a detailed demarcation line; Lithuanians agreed to retreat by September 7. The Polish regular army units did not cross the Foch Line, and refused to aid the PMO insurgents still operating on the Lithuanian side.
After the uprising, Poland repressed Lithuanian cultural life in Sejny. Lithuanian schools in Sejny (with some 300 pupils) and surrounding villages were closed, local Lithuanian clergy evicted, the Sejny Priest Seminary relocated. According to Lithuanians, the repressions were even more widespread, including a ban on public use of the Lithuanian language and the closure of Lithuanian organizations numbering 1,300 members. The New York Times, reporting on renewed hostilities a year later, described the 1919 Sejny events as a violent occupation, in which the Lithuanian inhabitants, teachers, and religious ministers were maltreated and expelled. Polish historian Łossowski notes that both sides mistreated the civilian population and exaggerated reports to gain internal and foreign support.
The uprising contributed to the deterioration of the Polish–Lithuanian relations and further discouraged the Lithuanians from joining Piłsudski's proposed Międzymorze federation. The Sejny Uprising doomed the Polish plan to overthrow the Lithuanian government in a coup d'état. The Lithuanian police and intelligence intensified their investigation of Polish sympathizers and the coup was soon uncovered. Mass arrests of Polish activists continued from August 27 to the end of September 1919. During the investigations lists of PMO supporters were found and the organisation was completely eliminated in Lithuania.
Hostilities over the Suwałki Region resumed in summer 1920. When Polish Army began to retreat during the course of the Polish–Soviet War, the Lithuanians moved to secure what they claimed to be their new borders, set by the Soviet–Lithuanian Peace Treaty of July 1920. The Peace Treaty granted Sejny and surrounding area to Lithuania. Poland did not recognize this bilateral treaty. Ensuing tensions grew into the Polish–Lithuanian War. Sejny changed hands frequently until it fell to Polish hands on September 22, 1920. The situation was legalized by the Suwałki Agreement of October 7, 1920, which returned to town to the Polish side of the border.
 Notes and references
- (Polish) Buchowski, Stanisław. "Powstanie Sejneńskie 23-28 sierpnia 1919 roku". Gimnazjum Nr. 1 w Sejnach. Retrieved 2007-09-27.
- (Polish) Mańczuk, Tadeusz (2001). "Z Orłem przeciw Pogoni. Powstanie sejneńskie 1919". Mówią Wieki. Retrieved 2007-09-27.
- Lesčius (2004), p. 276
- Lesčius (2004), p. 275
- Senn (1975), p. 158
- Buchowski, Krzysztof (2003). "Polish-Lithuanian Relations in Seinai Region at the Turn of the Nineteenth and Twentieth Centuries". The Chronicle of Lithuanian Catholic Academy of Sciences 2 (XXIII). Archived from the original on 2007-09-27.
- (Polish) "Powstanie Sejneńskie 1919". Association "Polish Community". Retrieved 2008-11-09.
- (Polish) "Historia". Urząd Miasta Sejny. Retrieved 2008-11-09.
- (Polish) Pisarska, Katarzyna. "Stosunki Polsko–Litewskie w latach 1926–1927". Archived from the original on 2010-10-09. Retrieved 2007-09-27.
- Lesčius (2004), p. 271
- (Lithuanian) Makauskas, Bronius (1999-08-13). Pietinės Sūduvos lietuviai už šiaudinės administracinės linijos ir geležinės sienos (1920–1991 m.). 27-30 (405-408). Voruta. ISSN 1392-0677.
- Łossowski (1995), p. 51
- Senn (1975), p. 133
- Lesčius (2004), p. 254
- Senn (1975), p. 132
- Lesčius (2004), pp. 254, 257
- Senn (1975), p. 135
- Senn (1975), p. 134
- (Polish) Łossowski, Piotr (1966). Stosunki polsko-litewskie w latach 1918-1920. Warsaw: Książka i Wiedza. p. 51. OCLC 9200888.
- Lesčius (2004), p. 272
- Lesčius (2004), p. 273
- Lesčius (2004), p. 274
- Łossowski (1995), p. 67
- Lesčius (2004), pp. 274–275
- Lesčius (2004), pp. 275–276
- Lesčius (2004), p. 277
- Lesčius (2004), p. 278
- Duranty, Walter (1920-09-06). "Poles Attacked By Lithuanians" (PDF). The New York Times.
- Łossowski (1995), p. 66
- Łossowski (1995), p. 68
- Lesčius (2004), p. 270
- Senn, Alfred Erich (1966). The Great Powers: Lithuania and the Vilna Question, 1920–1928. Studies in East European history. Brill Archive. p. 37. LCC 67086623.
- (Polish) Łossowski, Piotr (1995). Konflikt polsko-litewski 1918–1920. Warsaw: Książka i Wiedza. pp. 166–175. ISBN 83-05-12769-9.
- (Lithuanian) Lesčius, Vytautas (2004). Lietuvos kariuomenė nepriklausomybės kovose 1918-1920. Vilnius: Vilnius University, Generolo Jono Žemaičio Lietuvos karo akademija. ISBN 9955-423-23-4.
- (Polish) Łossowski, Piotr (1995). Konflikt polsko-litewski 1918-1920. Warszawa: Książka i Wiedza. ISBN 83-05-12769-9.
- Senn, Alfred Erich (1975) . The Emergence of Modern Lithuania. Greenwood Press. ISBN 0-8371-7780-4.