The February Revolution begins with strikes, demonstrations, and mutinies in Petrograd
Czar Nicholas II abdicates and includes his son. The following day, Nicholas' brother, Mikhail announced his refusal to accept the throne. Provisional Government formed
Lenin returns from exile and arrives in Petrograd via a sealed train
The July Days begin in Petrograd with spontaneous protests against the Provisional Government; after the Bolsheviks unsuccessfully try to direct these protests into a coup, Lenin is forced into hiding
Alexander Kerensky becomes Prime Minister of the Provisional Government
The Kornilov Affair, a failed coup by General Lavr Kornilov, commander of the Russian Army
The October Revolution - the Bolsheviks take over Petrograd
The Winter Palace, the last holdout of the Provisional Government, is taken by the Bolsheviks; the Council of People's Commissars (abbreviated as Sovnarkom), led by Lenin, is now in control of Russia
The Treaty of Brest-Litovsk, between Germany and Russia, is signed and takes Russia out of World War I
The Bolshevik Party changes its name to the Communist Party
Russian civil war begins
Czar Nicholas II and his family are executed
Russian civil war ends
Stalin is appointed General Secretary
The Union of Soviet Socialist Republics (U.S.S.R.) established
Lenin dies; Stalin will become his successor
The 1924 Soviet Constitution came into effect.
The Thirteenth Party Congress, led by Stalin, Comintern chairman Grigory Zinoviev and Politburo chairman Lev Kamenev, denounced Trotsky and his faction, the Left Opposition.
The Bukharan People's Soviet Republic was incorporated into the Uzbek SSR.
Trotsky was forced to resign his military offices.
Tikhon died. The Communist government would not allow elections to the patriarchate to be held; Metropolitan Peter of Krutitsy became the Patriarchal locum tenens according to his will.
The Uzbek SSR joined the Soviet Union.
Trotsky was expelled from the Politburo.
The Fourteenth Party Congress endorsed the leadership of Stalin and his rightist ally Nikolai Bukharin, soundly defeating the New Opposition faction of Kamenev and Zinoviev.
Sergius affirmed the loyalty of the Russian Orthodox Church to the Soviet government.
Trotsky and Zinoviev were expelled from the Communist Party.
The Fifteenth Party Congress expelled the remainder of the United Opposition from the Party.
First Five Year Plan: Stalin announced the beginning of state industrialisation of the Soviet economy.
Bukharin was expelled from the Politburo.
The Gulag was officially established.
Collectivisation in the USSR: The Central Executive Committee and the Sovnarkom issued the Decree about the Protection of Socialist Property, under which any theft of public property was punishable by death.
A decree by the Central Executive Committee and the Sovnarkom established a passport system in the Soviet Union.
First Five-Year Plan: It was announced that the plan had been fulfilled.
Elections to the Central Committee at the Seventeenth Party Congress revealed Sergey Kirov, the chief of the Leningrad Party, to be the most popular member.
Kirov was murdered by Leonid Nikolaev, possibly at the behest of Stalin.
Moscow Trials: The Trial of the Sixteen, in which Kamenev and Grigory Zinoviev were the primary defendants, began.
Moscow Trials: The defendants in the Trial of the Sixteen were executed.
The Stalin Constitution came into effect. The Central Executive Committee was renamed the Supreme Soviet of the Soviet Union.
Moscow Trials: The Second Trial began.
Moscow Trials: The Second Trial ended. Of seventeen defendants, all but four were sentenced to death.
Case of Trotskyist Anti-Soviet Military Organization: Mikhail Tukhachevsky, a Marshal of the Soviet Union and hero of the Russian Civil War, was arrested.
Case of Trotskyist Anti-Soviet Military Organization: Tukhachevsky was executed, with eight other military leaders.
Peter of Krutitsy was executed in solitary confinement.
Trial of the Twenty One: The third Moscow Trial, at which Bukharin was the primary defendant, began.
Trial of the Twenty One: The defendants were executed.
Soviet invasion of Poland (1939): The Red Army invaded Poland.
Shelling of Mainila: The Red Army shelled the Russian village of Mainila and blamed the Finns for invented casualties.
Winter War: The Soviet army attacked Finland.
Winter War: The Soviet Union established the Finnish Democratic Republic in the border town of Terijoki.
Winter War: The Moscow Peace Treaty was signed, ending the war at great cost to Finland and anticipating the evacuation of Finnish Karelia.
The Red Army occupied Lithuania.
The Red Army occupied Estonia and Latvia.
Soviet occupation of Bessarabia: Bessarabia and northern Bukovina were occupied by the Soviet Union.
The Lithuanian SSR was accepted into the Soviet Union.
The Latvian SSR was annexed by the Soviet Union.
Trotsky is assassinated by Ramon Mercador on Stalin's orders.
Operation Barbarossa: Three million Axis soldiers invaded the Soviet Union.
Continuation War: The Soviet Union launched a major air offensive against Finnish targets.
Battle of Moscow: Three German armies began an advance on Moscow.
Battle of Moscow: The Soviet army launched a counterattack from Kalinin.
Battle of Moscow: The Soviet counteroffensive ended between sixty and one-hundred fifty miles from Moscow.
The Red Army crossed into Poland.
Sergius died.
Soviet occupation of Romania: The Red Army captured Bucharest.
Continuation War: The Moscow Armistice was signed, ending the war at roughly the prewar borders.