Poznań and on January 16 he officially assumed his post, replacing Major Stanisław Taczak during the Greater Poland Uprising against Germany in the disputed region. During his service as the commander in chief of the Uprising, Dowbor-Muśnicki was responsible for almost complete reorganization of what was started as a para-military partisan force. He introduced conscription and mobilized eleven classes of recruits and reformed the partisans into divisions. During his command, the Greater Polish Army grew from merely 20,000 to over 100,000 soldiers, well-armed and well-equipped. After the Battle of Ławica in which the Poles managed to capture the airfield, the Greater Polish Army was the fourth force in the world in number of aeroplanes available. Dowbor-Muśnicki focused also on political matters and strived for political neutrality of the forces under his command, which made him demobilize some of the leftist and rightist officers. He also disbanded the leftist soldiers' councils. To some extent Dowbor-Muśnicki was conflicted with the Polish General Staff. Due to difficult diplomatic situation of Poland during the early stages of the Paris Peace Conference, the forces of the Greater Poland Uprising were separated from the Polish Army and were thought of as a separate entity. Because of that, he opposed drafting Poles from Greater Poland into the Polish Army and sending them to the fronts of the Polish-Ukrainian War and the Polish-Bolshevik War. Instead, he envisioned an offensive towards north which would spread the Uprising to the lands of Pomerania. However, after the area was peacefully transferred to Poland, his plans were made obsolete. Despite the conflict, on March 19, 1919 he was promoted to the rank of Generał broni, the highest rank of the Polish forces at that time. Finally, after the end of hostilities, on October 19, 1919 the Dowbor-Muśnicki's forces were merged with Józef Haller's Blue Army and the Polish Army while at the same time the lands of Greater Poland were officially incorporated into Poland. Retirement Józef Dowbor-Muśnicki remained the commander of the so-called Greater Poland Front until the outbreak of the Polish-Bolshevik War, after which he resigned his post and applied to Józef Piłsudski for a new assignment. After General Stanisław Szeptycki declined to take the post of the commanding officer of the Ukrainian Front from General Wacław Iwaszkiewicz, the post was offered to Dowbor-Muśnicki, who refused. Having no further assignments, in March 1920 he resigned all his posts in the army