Russia was the first country to adopt communism as its official ideology in 1917, following the Bolshevik Revolution led by Vladimir Lenin.

The Russian Social Democratic Labour Party (RSDLP) was the political party that led the Bolshevik Revolution in Russia in 1917. It was later renamed to the Communist Party of the Soviet Union (CPSU).

Joseph Stalin was the leader of the Soviet Union from 1924 to 1953. He succeeded Vladimir Lenin as the leader of the Communist Party of the Soviet Union (CPSU) and implemented a policy of rapid industrialization and collectivization of agriculture.

Joseph Stalin implemented a series of Five-Year Plans in the Soviet Union, which were economic plans that aimed to rapidly industrialize the country and increase agricultural production.

Mikhail Gorbachev implemented a policy of political and economic liberalization in the Soviet Union known as Perestroika, which aimed to restructure the economy and introduce democratic reforms.

Mikhail Gorbachev implemented a policy of openness and transparency in the Soviet Union known as Glasnost, which allowed for greater freedom of expression and access to information.

The collapse of the Soviet economy in the late 1980s and early 1990s, coupled with political instability and ethnic tensions, led to the dissolution of the Soviet Union in 1991.

After the collapse of communism, the former Soviet Union and Eastern Europe transitioned to a mixed economy, which combines elements of both capitalism and socialism.

Poland was the first country in Eastern Europe to break free from Soviet control in 1989, through a non-violent revolution led by the Solidarity movement.

The Velvet Revolution was a non-violent revolution that led to the overthrow of communism in Czechoslovakia in 1989.

Romania was the only country in Eastern Europe that experienced a violent revolution that led to the overthrow of communism in 1989, resulting in the execution of dictator Nicolae Ceausescu.

The Post-Soviet Crisis was a period of economic and political instability that affected the former Soviet Union and Eastern Europe in the 1990s, following the collapse of communism.

Moldova experienced the most severe economic decline during the Post-Soviet Crisis, with its GDP falling by over 60% in the early 1990s.

The Organization for Security and Cooperation in Europe (OSCE) was formed in 1995 to promote cooperation and security in Europe after the Cold War.

Poland, Hungary, and the Czech Republic all joined the European Union (EU) in 2004.