Born to a family of Orenburg Cossack origins in Zlatoust in the Urals, Shaposhnikov was a graduate of the Nicholas General Staff Academy and served in the Imperial Russian Army, reaching the rank of colonel during the First World War.

He was reappointed to the position following the Axis invasion of the Soviet Union in 1941, replacing Georgy Zhukov, but was again forced to resign a year later due to declining health.

[1] He joined the army of the Russian Empire in 1901 as an officer cadet, and graduated from the Nicholas General Staff Academy in 1910, reaching the rank of colonel in the Caucasus Grenadiers division in September 1917 during World War I.

[3] He was then demoted to command of the Volga Military District from April 1931 to 1932 as a result of slanderous accusations (made by an arrested staff-officer) of belonging to a clandestine organization.

In 1937 he was appointed as Chief of the General Staff, in succession to Alexander Ilyich Yegorov, a defendant of the Case of Trotskyist Anti-Soviet Military Organization secret trial during Joseph Stalin's Great Purge of the Red Army.

Stalin showed his admiration for the officer by always keeping a copy of Shaposhnikov's most important work, Mozg Armii (Мозг армии, "The Brain of the Army") (1929), on his desk.

[9] The resultant Winter War (1939–1940) did not deliver the immediate success the Soviet side had hoped for, and Shaposhnikov resigned as Chief of the General Staff in August 1940, due to ill-health and to disagreements with Stalin about the conduct of that campaign.

[4][5] Following the Axis invasion of the Soviet Union on 22 June 1941, he was reinstated (29 July 1941) as Chief of the General Staff[5] to succeed Georgy Zhukov,[4] and also became Deputy People's Commissar for Defence, the post he held until his career was cut short by ill-health in 1943.