Bolshevik Revolution: Czar Nicholas abdicates; Bolsheviks, led by Vladimir Ilyich Lenin, take control; Russian Soviet Socialist Republic established; capital moves to Moscow

Bolsheviks assassinate czar

Red Terror: Lenin purges Communist Party, socializes economy; 5 million die of famine

Lenin inaugurates New Economic Policy, allows limited free-market measures

Russia, Ukraine, Belorussia, Transcaucasia (present-day Armenia, Georgia, Azerbaijan) form Union of Soviet Socialist Republics

Joseph Stalin consolidates power; inaugurates first Five-Year Plan, collectivizes agriculture, industrializes; famine returns

Millions die in Stalin's Great Purge (through 1953)

Germany invades Russia

World War II ends; Russia occupies Eastern Europe, establishes puppet governments, Cold War takes shape

Soviets explode atomic device

Stalin dies; Nikita Khrushchev becomes first secretary of Communist Party

Khrushchev denounces Stalin

Soviets launch world's first manned space flight

Cuban Missile Crisis, Khrushchev withdraws missiles from Cuba

Leonid Brezhnev helps engineer Khrushchev's fall from power, becomes first secretary of Communist Party

Major border clashes with China

Détente: President Richard Nixon visits USSR, signs arms control treaties with Chairman Brezhnev

Soviets invade Afghanistan

General Secretary Mikhail Gorbachev attempts to improve faltering economy with glasnost (openness) and perestroika (restructuring)