Conflict between Poland and Lithuania after World War I (may 1919 – october 1920)
The Polish–Lithuanian War settled post-WWI control of Vilnius through military force, leaving Lithuania and Poland in a frozen conflict that lasted throughout the interwar period.
Key Facts
- Duration
- May 1919 – 29 November 1920
- Ceasefire signed
- 29 November 1920
- Vilnius ownership changes
- Up to 7 times between 1919 and 1920
- Suwałki Agreement signed
- 7 October 1920
- Central Lithuania incorporated
- Into Poland as Wilno Voivodeship in 1922
- Border recognized by Conference
- March 1923
By the Numbers
Location
Cause → Event → Consequence
After World War I, the dissolution of imperial powers left Lithuania and Poland both newly independent and competing for overlapping territories, especially Vilnius, which Lithuania claimed as its constitutional capital. The chaotic regional situation was further complicated by Soviet Russian expansion and German withdrawal, creating a power vacuum in which military confrontation became almost inevitable.
The Polish–Lithuanian War was fought primarily in the Vilnius and Suwałki regions from May 1919 to November 1920. Key episodes included Polish seizure of Vilnius in April 1919, Soviet capture and return of the city in 1920, the signing of the Suwałki Agreement, and General Żeligowski's staged mutiny on October 8, 1920, which captured Vilnius and led to the proclamation of the short-lived Republic of Central Lithuania.
Lithuania refused to accept Polish control of Vilnius, severing diplomatic relations with Poland for the entire interwar period. The Republic of Central Lithuania was absorbed into Poland in 1922, and the Conference of Ambassadors formalized the border in 1923. The International Court of Justice ruled in 1931 that Poland had violated international law, but the ruling had no practical effect on the territorial status quo.
Belligerents & Mobilization Analysis
Side A
1 belligerent
Lucjan Żeligowski, Józef Piłsudski.
Side B
1 belligerent