Yumashev was the son of a clerk. In 1910, he was expelled from the fifth grade of school, due to his family being unable to afford school fees. At the age of 15, he began to work as a shoemaker, worker at a cement factory and delivery man in the administration of the Transcaucasian Railways. After the death of his father, he moved with his mother to the village of
Kapustin Yar in
Astrakhan province, where he began to work as a clerk of a
volost government. In September 1912, he entered the Boatswain and Apprentices School in
Kronstadt. Yumashev joined the
Baltic Fleet, where he was assigned to the cruiser
Bogatyr. He served as a fireman and machinist, before being promoted to a
non-commissioned officer. Immediately after the
February Revolution of 1917, he was elected chairman of the
Sailors' Committee of the
Coastal Artillery in
Reval. In September 1917, he was dismissed from the Navy due to illness and returned to Krasny Yar. After the
October Revolution, he became chairman of the local
Committee of the Poor Peasants and chairman of a
Selsoviet. In August 1918, he joined the
Russian Communist Party, and became the commander of the Red Volunteer detachment. In February 1919, he voluntarily joined the
Red Army Naval Forces and participated in the
Russian Civil War on the ships of the
Astrakhan-Caspian and Volga-Caspian military flotillas. Serving as a gunner, senior gunner and battery commander, he fought on the
Volga River and the
Caspian Sea, and took part in the defense of
Astrakhan. From August 1920, Yumashev served in the Baltic Fleet. From 1920 to 1921, he was the commander of an artillery unit on the battleship
Marat, before serving as assistant commander of the ship. During the
Kronstadt Uprising in March 1921, he was arrested by the rebels and was in prison until the end of the storming of the fortress by the
Red Army. In 1924 he took part in the first long-distance cruise of the Soviet fleet, which involved the passage of the
Vorovskiy messenger ship from
Arkhangelsk to
Vladivostok. In 1925, he educated at special courses for commanding officers of the fleet. Yumashev served on the destroyers
Lenin and
Voikov, which was assigned to the Baltic Fleet. He served as second assistant to the commander of the battleship
Marat in 1932. In 1926 he transferred to the
Black Sea Fleet as captain of the
cruiser Komintern. He subsequently commanded the cruiser
Profintern and destroyer flotillas. In 1932, he attended tactical courses for commanders of ships at the
Naval Academy. With the introduction of personal military ranks in the USSR, by order of the People's Commissar of Defense of the USSR No. 2488 of November 28, 1935, I. S. Yumashev was awarded the military rank of flagship of the 2nd rank. In September 1937, he became chief of staff of the Black Sea Fleet and in January 1938 commander of the Black Sea Fleet. ==World War II==