Sergei Kirov

Sergei Mironovich Kirov (born Kostrikov; 27 March 1886 – 1 December 1934) was a Russian and Soviet politician and Bolshevik revolutionary. Kirov was an early revolutionary in the Russian Empire and member of the Bolshevik faction of the Russian Social Democratic Labour Party. Kirov became an Old Bolshevik and personal friend to Joseph Stalin, rising through the Communist Party of the Soviet Union ranks to become head of the party in Leningrad and a member of the Politburo.
On 1 December 1934, Kirov was shot and killed by Leonid Nikolaev at his offices in the Smolny Institute. Nikolaev and several alleged accomplices were convicted in a show trial and executed less than 30 days later. Kirov’s assassination was used by Stalin as a reason for starting the Moscow trials and the Great Purge. Based on circumstantial evidence, a number of historians concluded that the assassination was ordered by Stalin.