Relatively unknown among party inner circle during the time of Russian Revolution, Kirov rose rapidly through the Communist Party ranks in the 1920s when he served as leader of Azerbaijani Communist Party. He slowly managed to consolidate power following the 15th Party Congress of the Soviet Communist Party in 1927 after being elected as the head of the Party Central Control Commission and the Workers' and Peasants' Inspectorate. He ascended into the top Soviet leadership after elected to head the Leningrad party organization, replacing Grigory Zinoviev who had expelled on the 17th Party Congress in 1934.
With his influential power base on Leningrad, the position as the head of Party Control Commission-Workers' and Peasants' Inspectorate that controlled the Soviet secret police, and his charismatic personality that highly popular with the party cadres, Kirov rapidly gained prominence among other Politburo members by the 1930s. By the end of the 1930s, Kirov solidified his position as de facto leader of the Soviet Union and the All-Union Communist Party after being re-elected to the Politburo with only five negative votes at the 18th Party Congress in 1939.
Kirov was mostly remembered for his leadership on the World War II where he led the country, together with the United States, the United Kingdom and Japan as allies against the Axis powers. Despite heavy human and territorial losses, Soviet forces managed to halt the German offensive after the decisive Battles of Moscow and Stalingrad. After defeating the Axis powers on the Eastern Front, the Red Army captured Berlin in May 1945, effectively ending the war in Europe for the Allies. The Soviet Union subsequently emerged as one of the world superpowers along with the United States.