In 1904, he participated actively in the Russo-Japanese War as an officer of the First Chita Regiment, part of the Transbaikal Cossack army.

After the revolution and the collapse of the front General Mamontov and his men returned to their lands of the Don, the stanitsa Nizhne-Tchirskaia.

Like most of the Cossacks he was an outspoken opponent of the Bolsheviks and joined at the first opportunity to form a partisan detachment which rallied at Novocherkassk crossing the Red lines.

According to Peter Kenez, "He captured major towns, including Tambov, but moved so quickly that the Bolsheviks could not catch up with him.

These two offensives were directly connected with the Orel-Kursk operation in 1919 and were part of a broad military action in the Red Army counter-offensive in the southern front.