The second volume of the publication includes documents and materials relating to the period from April 12 (24), 1877 to February 19 (March 3), 1878, i.e., from Russia's declaration of war on Turkey to the signing of the San Stefano Preliminary Peace Treaty, as well as some later documents related to this period. In total, the second volume contains 499 documents (362 for 1877, 137 for 1878). To prepare this work, materials from 295 funds in the vaults of the USSR and 118 funds in the vaults of Bulgaria were examined.