Aleksey Kaledin was born into a family of Don Cossack. He studied at the 2nd military Konstantinovsky school and Mikhailovsky artillery school (1882), and graduated from the Nicholas General Staff Academy (1889). He served in the Warsaw Military District, then on the Don as deputy Chief-of-Staff of the Don Army. A participant of World War I, since March 1916, he held the post of Commander of the 8th Army. General of the Cavalry (1916). In May 1917, the Provisional Government removed Kaledin from the command of the army for failure to comply with the orders on democratization in the army. In June 1917, he left for the Don. He was elected Ataman [commander] of the Don Cossack Host by the Great Host Krug [assembly].

On September 1, Minister of War of the Provisional Government, Aleksander Verkhovsky, ordered the arrest of Kaledin over alleged participation in Kornilov affair. However, the Host Government refused to fulfill the order, and on September 4, Aleksander Kerensky canceled it, subject to the “guarantee” of the Host Government for Kaledin.

Kaledin considered the October coup of 1917 a crime, stating that the Don Host Government would provide full support to the Provisional Government, and he would assume full power in the Don until it was restored. He made an attempt to unite all anti-Soviet forces, establishing contact with Stavka [the Headquarters], the Ukrainian Central Rada, Cossack military governments of the Kuban, Terek, and Orenburg. He was elected to the All-Russian Constituent Assembly in the Donskoy constituency on list No. 4 (Cossacks).

On December 18, 1917, Kaledin together with generals Mikhail Alekseyev and Lavr Kornilov, established the Don Civil Council, which claimed the status of the All-Russian Government, in which he was in charge of the Don and the Don Cossack Host. Late December 1917 saw the Red troops begin an offensive against the Kaledin forces. In January 1918, the Congress of Frontline Cossacks declared ataman Kaledin deposed and recognized the authority of the Council of People’s Commissars headed by Vladimir Lenin. The Don Cossacks community was split, the forces loyal to Kaledin failed to stop the advance of the Soviet troops. General Kornilov informed Kaledin of the decision to withdraw the Volunteer Army to the Kuban. On January 29, 1918, Kaledin convened a meeting of the government, at which he resigned as a Host Ataman. On the same day, he committed suicide. In his suicide letter to General Alekseyev, he referred to the “refusal of the Cossacks to follow their ataman” explaining his actions.