After the Battle of Kaniów on 11 May 1918, in which the forces of the 2nd Brigade broke through the front and created the 2nd Corps, the Polish commanders entered the alliance with one of the White generals, Mikhail Alekseev, and his Volunteer Army in the northern Caucasus near the Kuban River. By September 1918 the Polish forces in the region, called the 'Polish Unit of the Volunteer Army', numbered over 700 people under the command of Col. Franciszek Zieliński, and were engaged in several battles with the Bolsheviks.