Union of Soviet Socialist Republics

State · 1922–1991 CE · at its largest around 1946 CE

The world's first communist state set out to build a new society by plan, through forced collectivization, the Gulag and immense sacrifice against Hitler. It sent Sputnik and Yuri Gagarin into space, produced Shostakovich and Solzhenitsyn, and spent decades locked in Cold War rivalry with America.

On its lands while it lasted

Joseph Stalin (1878 CE – 1953 CE): Georgian-born dictator of the Soviet Union from the late 1920s until his death. He drove forced industrialisation and collectivisation, led the country to victory in World War II, and oversaw mass repression.
Albert Einstein (1879 CE – 1955 CE): German-born theoretical physicist who developed the special and general theories of relativity and explained the photoelectric effect, for which he won the 1921 Nobel Prize in Physics.
Adolf Hitler (1889 CE – 1945 CE): Austrian-born dictator of Nazi Germany from 1933 to 1945. He started World War II in Europe and bears chief responsibility for the Holocaust. He died by suicide in Berlin.
Mao Zedong (1893 CE – 1976 CE): Communist revolutionary who founded the People's Republic of China and led it until his death.
Russian Revolution (1917–1923 CE): The February Revolution of 1917 in Petrograd ended the rule of the tsars, and the October Revolution brought Lenin’s Bolsheviks to power. After a civil war they founded the Soviet Union in 1922.
Yuri Gagarin (1934 CE – 1968 CE): Soviet pilot and cosmonaut who became the first human in space when Vostok 1 carried him once around the Earth on 12 April 1961. He died in a training jet crash in 1968.
World War II in Europe (1939–1945 CE): The European theatre of the deadliest war in history, from Germany's invasion of Poland in 1939 to its surrender in May 1945. Tens of millions died, including six million Jews in the Holocaust.
Auschwitz concentration camp (1940–1945 CE): The largest Nazi concentration and extermination camp, built in occupied Poland. About 1.1 million people, the great majority of them Jews, were murdered there before its liberation in January 1945.
Battle of Stalingrad (1942–1943 CE): From August 1942 to February 1943 the Red Army defended Stalingrad and then encircled the German Sixth Army, which surrendered. It was a turning point of World War II.
Cold War (1947–1991 CE): The rivalry between the United States and the Soviet Union and their allies, fought through an arms race, proxy wars and the space race rather than direct war. Divided Berlin was its emblem; it ended with the collapse of the Soviet Union in 1991.
People's Republic of China founded (1949 CE): Mao Zedong proclaimed the People's Republic of China from Tiananmen Gate on 1 October 1949.
Korean War (1950–1953 CE): War between North Korea, backed by China and the Soviet Union, and South Korea, backed by UN forces led by the United States.
Sputnik 1 (1957 CE): The first artificial Earth satellite, launched from Baikonur by the Soviet Union on 4 October 1957, beginning the Space Age.
First human in space (1961 CE): Yuri Gagarin became the first human in space, orbiting the Earth once on 12 April 1961 after launch from Baikonur.
Cultural Revolution (1966–1976 CE): Political campaign launched by Mao against perceived enemies within the party and society, bringing mass persecution and violence.