Communist Party of the Soviet Union in the context of "Armenian Soviet Socialist Republic"

The Bolsheviks, led by Vladimir Lenin, were a radical faction of the Marxist Russian Social Democratic Labour Party (RSDLP) which split with the Mensheviks at the Second Party Congress in 1903. The Bolshevik party, formally established in 1912, seized power in Russia in the October Revolution of 1917 and was later renamed the Russian Communist Party, All-Union Communist Party, and ultimately the Communist Party of the Soviet Union. Its ideology, based on Leninist and later Marxist–Leninist principles, became known as Bolshevism.

The origin of the RSDLP split was Lenin's support for a smaller party of professional revolutionaries, as opposed to the Menshevik desire for a broad party membership. The influence of the factions fluctuated in the years up to 1912, when the RSDLP formally split in two. The political philosophy of the Bolsheviks was based on the Leninist principles of vanguardism and democratic centralism. Lenin was also more willing to use illegal means such as robbery to fund the party's activities. By 1917, influenced by the experiences of World War I, he reached the conclusion that the chain of world capitalism could "break at its weakest link" in Russia before it assumed the level of the advanced countries, opposing theorists such as Georgi Plekhanov. Lenin had also come to view poorer peasants as potential allies of the relatively small Russian proletariat.

The Ukrainian Soviet Socialist Republic, abbreviated as the Ukrainian SSR, UkrSSR, and also known as Soviet Ukraine or just Ukraine, was one of the constituent republics of the Soviet Union from 1922 until 1991. Under the Soviet one-party model, the Ukrainian SSR was governed by the Communist Party of the Soviet Union through its republican branch, the Communist Party of Ukraine.

The first iterations of the Ukrainian SSR were established during the Russian Revolution, particularly after the Bolshevik Revolution. The outbreak of the Ukrainian–Soviet War in the former Russian Empire saw the Bolsheviks defeat the independent Ukrainian People's Republic, during the conflict against which they founded the Ukrainian People's Republic of Soviets, which was governed by the Russian Soviet Federative Socialist Republic (RSFSR), in December 1917; it was later succeeded by the Ukrainian Soviet Republic in 1918. Simultaneously with the Russian Civil War, the Ukrainian War of Independence was being fought among the different Ukrainian republics founded by Ukrainian nationalists, Ukrainian anarchists, and Ukrainian separatists – primarily against Soviet Russia and the Ukrainian SSR, with either help or opposition from neighbouring states. In 1922, it was one of four Soviet republics (with the Russian SFSR, the Byelorussian SSR, and the Transcaucasian SFSR) that signed the Treaty on the Creation of the Soviet Union. As a Soviet quasi-state, the Ukrainian SSR became a founding member of the United Nations in 1945 alongside the Byelorussian SSR, in spite of the fact that they were also legally represented by the Soviet Union in foreign affairs. Upon the dissolution of the Soviet Union in 1991, the Ukrainian SSR emerged as the present-day independent state of Ukraine, although the modified Soviet-era constitution remained in use until the adoption of the modern Ukrainian constitution in June 1996.

The Union of Soviet Socialist Republics (USSR), commonly known as the Soviet Union, was a transcontinental country that spanned much of Eurasia from 1922 until it dissolved in 1991. During its existence, it was the largest country by area, extending across eleven time zones and sharing borders with twelve countries, and the third-most populous country. An overall successor to the Russian Empire, it was nominally organized as a federal union of national republics, the largest and most populous of which was the Russian SFSR. In practice, its government and economy were highly centralized. As a one-party state governed by the Communist Party of the Soviet Union (CPSU), it was the flagship communist state. Its capital and largest city was Moscow.

The Soviet Union's roots lay in the October Revolution of 1917. The new government, led by Vladimir Lenin, established the Russian SFSR, the world's first constitutionally communist state. The revolution was not accepted by all within the Russian Republic, resulting in the Russian Civil War. The Russian SFSR and its subordinate republics were merged into the Soviet Union in 1922. Following Lenin's death in 1924, Joseph Stalin came to power, inaugurating rapid industrialization and forced collectivization that led to significant economic growth but contributed to a famine between 1930 and 1933 that killed millions. The Soviet forced labour camp system of the Gulag was expanded. During the late 1930s, Stalin's government conducted the Great Purge to remove opponents, resulting in large scale deportations, arrests, and show trials accompanied by public fear. Having failed to build an anti-Nazi coalition in Europe, the Soviet Union signed a non-aggression pact with Nazi Germany in 1939. Despite this, in 1941 Germany invaded the Soviet Union in the largest land invasion in history, opening the Eastern Front of World War II. The Soviets played a decisive role in defeating the Axis powers while liberating much of Central and Eastern Europe. However they would suffer an estimated 27 million casualties, which accounted for most losses among the victorious Allies. In the aftermath of the war, the Soviet Union consolidated the territory occupied by the Red Army, forming satellite states, and undertook rapid economic development which cemented its status as a superpower.

The Communist Party of China (CPC), commonly known as the Chinese Communist Party (CCP), is the founding and ruling party of the People's Republic of China (PRC). Founded in 1921, the CCP won the Chinese Civil War against the Kuomintang and proclaimed the establishment of the PRC under the chairmanship of Mao Zedong in October 1949. The CCP has since governed China and has had sole control over the country's armed forces and law enforcement. As of 2024, the CCP has more than 100 million members, making it the second largest political party by membership in the world.

In 1921, Chen Duxiu and Li Dazhao founded the CCP with the help of the Far Eastern Bureau of the Russian Communist Party (Bolsheviks) and Far Eastern Bureau of the Communist International. Although the CCP aligned with the Kuomintang (KMT) during its initial years, the rise of the KMT's right-wing under the leadership of Chiang Kai-shek and subsequent massacres of tens of thousands of CCP members resulted in a split and a prolonged civil war between the CCP and KMT. During the next ten years of guerrilla warfare, Mao Zedong rose to become the most influential figure in the CCP and the party established a strong base among the rural peasantry with its land reform policies. Support for the CCP continued to grow throughout the Second Sino-Japanese War. After the Japanese surrender in 1945, the CCP emerged triumphant in the communist revolution against the Nationalist government. The CCP established the People's Republic of China on 1 October 1949 and the remnants of the Nationalist government retreated to Taiwan shortly after.

In the Soviet Union, a Union Republic (Russian: Сою́зная Респу́блика, romanized: Soyúznaya Respúblika) or unofficially a Republic of the USSR was a constituent federated political entity with a system of government called a Soviet republic, which was officially defined in the 1977 constitution as "a sovereign Soviet socialist state which has united with the other Soviet republics to form the Union of Soviet Socialist Republics" and whose sovereignty is limited by membership in the Union. As a result of its status as a sovereign state, the Union Republic de jure had the right to enter into relations with foreign states, conclude treaties with them and exchange diplomatic and consular representatives and participate in the activities of international organizations (including membership in international organizations). The Union Republics were perceived as national-based administrative units of the Union of Soviet Socialist Republics (USSR).

The Soviet Union was formed in 1922 by a treaty between the Soviet republics of Byelorussia, Russian SFSR (RSFSR), Transcaucasian Federation, and Ukraine, by which they became its constituent republics of the Union of Soviet Socialist Republics (Soviet Union). For most of its history, the USSR was a one-party state led by the Communist Party of the Soviet Union. Key functions of the USSR were highly centralized in Moscow until its final years, despite its nominal structure as a federation of republics; the light decentralization reforms during the era of perestroika (reconstruction) and glasnost (voice-ness, as in freedom of speech) conducted by Mikhail Gorbachev as part of the Helsinki Accords are cited as one of the factors which led to the dissolution of the USSR in 1991 as a result of the Cold War and the creation of the Commonwealth of Independent States.

The Polish United Workers' Party (Polish: Polska Zjednoczona Partia Robotnicza [ˈpɔlska zjɛdnɔˈt͡ʂɔna ˈpartja rɔbɔtˈɲit͡ʂa], PZPR) was the communist party which ruled the Polish People's Republic as a one-party state from 1948 to 1989. The PZPR had led two other legally permitted subordinate minor parties together as the Front of National Unity and later Patriotic Movement for National Rebirth. The Polish United Workers' Party had total control over public institutions in the country as well as the Polish People's Army, the UB and SB security agencies, the Citizens' Militia (MO) police force and the media.

The falsified 1947 Polish legislative election granted the Communist Polish Workers' Party (PPR) complete political authority in post-war Poland. The PZPR was founded forthwith in December 1948 through the unification of the PPR and the Polish Socialist Party (PPS). From 1952 onward, the position of "First Secretary" of the Polish United Workers' Party was de facto equivalent to Poland's head of state. Throughout its existence, the PZPR maintained close ties with ideologically-similar parties of the Eastern Bloc, most notably the Socialist Unity Party of Germany, Communist Party of Czechoslovakia and the Communist Party of the Soviet Union. Between 1948 and 1954, nearly 1.5 million individuals registered as Polish United Workers' Party members, and membership rose to 3 million by 1980.

The Great Purge or Great Terror (Russian: Большой террор, romanized: Bol'shoy terror), also known as the Year of '37 (37-й год, Tridtsat' sed'moy god) and the Yezhovshchina (ежовщина [(j)ɪˈʐofɕːɪnə], lit. 'period of Yezhov'), was a political purge in the Soviet Union from 1936 to 1938. After the assassination of Sergei Kirov by Leonid Nikolaev in 1934, Joseph Stalin launched a series of show trials known as the Moscow trials to remove suspected dissenters from the Communist Party of the Soviet Union (especially those aligned with the Bolshevik party). The term "great purge" was popularized by historian Robert Conquest in his 1968 book, The Great Terror, whose title alluded to the French Revolution's Reign of Terror.

The purges were largely conducted by the NKVD (People's Commissariat for Internal Affairs), which functioned as the interior ministry and secret police of the USSR. In 1936, the NKVD under Genrikh Yagoda began the removal of the central party leadership, Old Bolsheviks, government officials, and regional party bosses. Soviet politicians who opposed or criticized Stalin were removed from office and imprisoned, or executed, by the NKVD. The purges were eventually expanded to the Red Army high command, which had a disastrous effect on the military. The campaigns also affected many other segments of society: the intelligentsia, wealthy peasants—especially those lending money or other wealth (kulaks)—and professionals. As the scope of the purge widened, the omnipresent suspicion of saboteurs and counter-revolutionaries (known collectively as wreckers) began affecting civilian life.

The General Secretary of the Central Committee of the Communist Party of the Soviet Union was the leader of the Communist Party of the Soviet Union (CPSU). From 1924 until the country's dissolution in 1991, the officeholder was the recognized leader of the Soviet Union. Prior to Joseph Stalin's accession, the position was not viewed as an important role in Vladimir Lenin's government and previous occupants had been responsible for technical rather than political decisions.

Officially, the General Secretary solely controlled the Communist Party directly. However, since the party had a monopoly on political power, the General Secretary de facto had executive control of the Soviet government. Because of the office's ability to direct both the foreign and domestic policies of the state and preeminence over the Soviet Communist Party, it was the de facto highest office of the Soviet Union.

Boris Nikolayevich Yeltsin (1 February 1931 – 23 April 2007) was a Russian politician and statesman who served as President of Russia from 1991 to 1999. He was a member of the Communist Party of the Soviet Union (CPSU) from 1961 to 1990. He later stood as a political independent, during which time he was viewed as being ideologically aligned with liberalism.

Yeltsin was born in Butka, Ural Oblast. Growing up in Kazan and Berezniki, he worked in construction after studying at the Ural State Technical University. After joining the Communist Party, he rose through its ranks, and in 1976, he became First Secretary of the party's Sverdlovsk Oblast committee. Yeltsin was initially a supporter of the perestroika reforms of Soviet leader Mikhail Gorbachev. He later criticized the reforms as being too moderate and called for a transition to a multi-party representative democracy. In 1987, he was the first person to resign from the Politburo of the Communist Party of the Soviet Union, which established his popularity as an anti-establishment figure and after which he earned the reputation of the leader of the anti-communist movement. In 1990, he was elected chair of the Russian Supreme Soviet and in 1991 was elected president of the Russian Soviet Federative Socialist Republic (RSFSR), becoming the first popularly-elected head of state in Russian history. Yeltsin allied with various non-Russian nationalist leaders and was instrumental in the formal dissolution of the Soviet Union in December of that year. With the dissolution of the Soviet Union, the RSFSR became the Russian Federation, an independent state. Through that transition, Yeltsin remained in office as president. He was later re-elected in the 1996 Russian presidential election, which critics assert was rigged.