Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Soviet 21st Army was a field army of the Red Army during World War II.21st Army was a part of the Second Operational Echelon of the RKKA. It was formed from the forces of the Volga Military District in May 1941 and was initially based on 63rd Rifle Corps and 66th Rifle Corps. The army was under the command of Lieutenant-General Vasilii Gerasimenko, and its chief of staff was Major-General Vasilii Gordov. The commander of 63rd Rifle Corps was Lieutenant-General Leonid Petrovskii and the commander of 66th Rifle Corps was Major-General Fedor Sudakov. In early June the army, subordinated to the command of Western Front, was moved to the eastern fringes of the Pripyat Marshes south of Homel. At the outbreak of hostilities on 22 June the army was redeployed north to defend the right bank of the Dnepr between Rybchev and Stary-Bykhov. At the same time 25th Mechanised Corps, under the command of Major-General Semen Krivoshein, was assigned to 21st Army from the Kharkov Military District.