1st Lithuanian–Belarusian Division

The 1st Lithuanian–Belarusian Division (1. Dywizja Litewsko-Białoruska, 1-ая Літоўска-Беларуская дывізія) was a volunteer unit of the Polish Army formed around December 1918 and January 1919 during the Polish–Soviet War. It was created out of several dozen smaller units of self-defence forces created out of local volunteers in what is now Lithuania and Belarus amidst a growing series of territory disputes between the Second Polish Republic, the Russian SFSR and several others local provisional governments and took part in several key battles of the war.

Predecessors
With the end of the World War I, a growing series of territorial disputes between Poland, Soviet Russia and several other local provisional governments erupted in a series of wars in Central and Eastern Europe, the most prominent of these being the Polish–Soviet War. Starting in the last years of the First World War, many smaller units of self-defence forces were created out of local volunteers in those areas, among them likely the best known being the Lithuanian and Belarusian Self-Defence ('Samoobrona Litwy i Białorusi'). Self-Defence units were organized in the areas of the Kresy region with Polish majorities or significant minorities – usually urbanized areas like the cities of Vilnius, Minsk, Hrodna, Lida and Kaunas, or towns like Ašmiany, Wilejka, Nemenčinė, Świr and Panevėžys; until December 1918 those units had no central command or organization and many of them were named after the local cities or regions (like 'Samoobrona Lidy'). The first task of those units was curbing the crime wave by German deserters, and later, defence from the pro-Bolshevik groups. Despite its name, most of the members of that organization were either Poles or polonized, and therefore supported the cause of attaching those territories with the newly recreated Polish state.

Operational history
The initial core of the future division was formed in December 1918 in Minsk, where a group of roughly 1500 Poles and Belarusians rose to arms to defend the city against the advancing forces of Soviet Russia. However, due to Russian numerical superiority and lack of support from the side of the short-lived Belarusian National Republic, the group withdrew towards central Poland. Other such self-defence groups, resistance organizations and veterans of the Green Army of the Russian Civil War also reached Poland, where they were reformed into a single unit under the command of general Władysław Wejtko.

Another large group of volunteers to join the division were the remnants of roughly 2,500 men strong force created in Vilnius to defend it against the Reds in January 1919. In the effect of four-day-long fights for the city and the area of Nowa Wilejka, the Polish forces were pushed back and the city had to be abandoned. The newly formed division took part in the Battle of Brześć Litewski of January 8 of that year, one of the first battles of the Polish–Soviet War.

The division, commanded by Gen. Jan Rządkowski, took part in many of the largest battles of that conflict. Among others, it played a major role in the Battle of Radzymin, a part of the Battle of Warsaw, the decisive struggle of the war. It also took part in the Battle of the Niemen, where it suffered heavy losses. Finally, two days prior to the cease fire ending the war, the units of the division – then commanded by Gen. Lucjan Żeligowski – took over Vilnius Region from the Lithuanian forces and formed the core of the armed forces of the Republic of Central Lithuania.

Following the elections held there and that state's merger with Poland in 1923, the division was partially demobilized, while its remnants were incorporated into the Polish 19th Infantry Division stationed in Vilnius (Polish: Wilno).