The monograph is dedicated to the longest war between Russia and Turkey and the participation of Russian Cossacks in it. The Russo-Turkish War of 1806-1812 was a kind of dress rehearsal for the Patriotic War of 1812. Russian troops under the leadership of M.I. Kutuzov were surrounded, starved and forced to surrender the Turkish army. The monograph shows the role and place of the Cossacks in this war, reveals the principles of the organization of Cossack troops, the system of Cossack education, Cossack tactics and the characteristics of the behavior of the Cossacks in the war. Russian commanders M. I. Kutuzov, A. A. Prozorovsky, P. I. Bagration and commanders of Cossack units M. I. Platov, A. K. are described.