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 disputed Republic of Central Lithuania.