ENThe article discusses the process of forming and organizing the Lithuanian-Volyn Legion during the November Uprising until it became subordinated to Governmental War Commission in April 1831. The preserved source materials allowed for a detailed analysis of the problems that arose during the implementation of the project. Considerable attention is devoted to political issues that ultimately led to the establishment of the formation and the role of officers who were personally involved in all activities for the benefit of the unit. The issue of uniforms and supplies for the soldiers of the Lithuanian-Volyn Legion is also discussed. Finally, the actual participation of the formation during the Battle of Grochów on 25 February 1831, is presented, evidence for which was obtained through an analysis of reports from the Polish commanders and the diaries and accounts of the combatants. Key words: Grochów, Kingdom of Poland, Lithuanian-Volyn Legion, Lithuania, November Uprising, war of 1831.