Communist International in the context of "Far Eastern Bureau of the Communist International"

Marxism–Leninism (Russian: марксизм-ленинизм, romanized: marksizm-leninizm) is a communist ideology that became the largest faction of the communist movement in the world in the years following the October Revolution. It was the predominant ideology of most communist governments throughout the 20th century. It was developed in the Union of Soviet Socialist Republics by Joseph Stalin and drew on elements of Bolshevism, Leninism, and Marxism. It was the state ideology of the Soviet Union, Soviet satellite states in the Eastern Bloc, and various countries in the Non-Aligned Movement and Third World during the Cold War, as well as the Communist International after Bolshevization.

Today, Marxism–Leninism is the de jure ideology of the ruling parties of China, Cuba, Laos, and Vietnam, as well as many other communist parties. The state ideology of North Korea is derived from Marxism–Leninism, although its evolution is disputed.

The Anti-Comintern Pact, officially the Agreement against the Communist International was an anti-communist pact concluded between Nazi Germany and the Empire of Japan on 25 November 1936 and was directed against the Communist International (Comintern). It was signed by German ambassador-at-large Joachim von Ribbentrop and Japanese ambassador to Germany Kintomo Mushanokōji. Italy joined in 1937 (earlier it had signed the Italo-Soviet Pact directed partly against Hitler), but it was legally recognized as an original signatory by the terms of its entry. Spain and Hungary joined in 1939. Other countries joined during World War II.

The Japanese signatories had hoped that the Anti-Comintern Pact would effectively be an alliance against the Soviet Union, which was how the Soviets perceived it. There was also a secret additional protocol which specified a joint German-Japanese policy specifically aimed against the Soviet Union.

The International Brigades (Spanish: Brigadas Internacionales) were volunteer soldiers organized by the Communist International to assist the Popular Front government of the Second Spanish Republic during the Spanish Civil War. The International Brigades existed for two years, from 1936 until 1938. It is estimated that during the entire war, there were some 32,000 Brigaders, yet at no single moment were there more than 18,000 actually deployed. Beyond the Spanish Civil War, "International Brigades" is also sometimes used interchangeably with the term foreign legion in reference to military units comprising foreigners who volunteer to fight in the military of another state, often in times of war.

The headquarters of the brigade was located at the Gran Hotel, Albacete, Castilla-La Mancha. They participated in the battles of Madrid, Jarama, Guadalajara, Brunete, Belchite, Teruel, Aragon, and the Ebro. Most of these ended in defeat. For the last year of its existence, the International Brigades were integrated into the Spanish Republican Army as part of the Spanish Foreign Legion. The organisation was dissolved on 23 September 1938 by Spanish Prime Minister Juan Negrín in a vain attempt to get more support from the liberal democracies on the Non-Intervention Committee.

The Long March (Chinese: 长征; pinyin: Chángzhēng; lit. 'Long Expedition') was a military retreat by the Chinese Red Army and Chinese Communist Party (CCP) from advancing Kuomintang (KMT) forces during the Chinese Civil War, occurring between October 1934 and October 1935. About 100,000 troops retreated from the Jiangxi Soviet and other bases to a new headquarters in Yan'an, Shaanxi, traversing some 10,000 kilometres (6,000 miles). About 8,000 troops ultimately survived the Long March.

After the defeat of the Red Army in Chiang Kai-shek's Fifth Encirclement Campaign, on 10 October 1934 the CCP decided to abandon its Jiangxi Soviet and headquarters in Ruijin, Jiangxi. The First Front Red Army of some 86,000 troops headed west, traveling over the rugged terrain of China's western provinces, including eastern Tibet. The Red Army broke several of Chiang's blockades with heavy losses, and by the time it crossed the Xiang River on 1 December had only 36,000 men left. Its leaders, including Comintern military adviser Otto Braun and Moscow-trained Bo Gu, decided to take the troops through Hunan, but Chiang set up defenses to block their way. Mao Zedong, who was not a member of the Politburo, suggested going through Guizhou instead, which was accepted. On New Year's Day 1935, the Red Army crossed the Wu River, and a week later held the Zunyi Conference, which reduced Soviet influence in the Politburo and established Mao's position as de facto leader.

A communist party is a political party that seeks to realize the socio-economic goals of communism. The term "communist party" was popularized by the title of The Manifesto of the Communist Party (1848) by Karl Marx and Friedrich Engels. As a vanguard party, the communist party guides the political education and development of the working class (proletariat). As a ruling party, the communist party exercises power through the dictatorship of the proletariat. Vladimir Lenin developed the idea of the communist party as the revolutionary vanguard, when the socialist movement in Imperial Russia was divided into ideologically opposed factions, the Bolshevik faction ("of the majority") and the Menshevik faction ("of the minority"). To be politically effective, Lenin proposed a small vanguard party managed with democratic centralism which allowed the centralized command of a disciplined cadre of professional revolutionaries. Once a policy was agreed upon, realizing political goals required every Bolshevik's total commitment to the agreed-upon policy.

In contrast, the Menshevik faction, which initially included Leon Trotsky, emphasized that the party should not neglect the importance of mass populations in realizing a communist revolution. In the course of the revolution, the Bolshevik party which became the Communist Party of the Soviet Union (CPSU) assumed government power in Russia after the October Revolution in 1917. With the creation of the Communist International (Comintern) in 1919, the concept of communist party leadership was adopted by many revolutionary parties, worldwide. In an effort to standardize the international communist movement ideologically and maintain central control of the member parties, the Comintern required that its members use the term "communist party" in their names.

The Romanian Social Democratic Party (Romanian: Partidul Social Democrat Român, or Partidul Social Democrat, PSD) was a social-democratic political party in Romania. In the early 1920s, the Socialist Party of Romania split over the issue of affiliation with the Third International. The majority, which supported affiliation, evolved into the Communist Party of Romania in 1921, while the members who opposed the new orientation formed various political groupings, eventually reorganizing under a central leadership in 1927. From 1938 to 1944, the party was outlawed but remained active in clandestinity. After 1944, it allied with the Communists and eventually was forced to reunite with them to form the Workers' Party of Romania in 1948. It published the magazines Socialismul, Lumea Nouă, and Libertatea. After the end of the Communist single-party system in 1989, a group of former members created a new party which proclaimed itself the direct descendant of the PSD.

The French Communist Party (French: Parti communiste français, pronounced [paʁti kɔmynist fʁɑ̃sɛ], PCF) is a communist party in France. The PCF is a member of the Party of the European Left.

The PCF was founded in 1920 by Marxist–Leninist members of the French Section of the Workers' International (SFIO) who supported the Bolsheviks in the 1917 Russian Revolution. It became a member of the Communist International, and followed a Marxist-Leninist line under the leadership of Maurice Thorez. In response to the threat of fascism, the PCF joined the socialist Popular Front which won the 1936 election, but it did not participate in government. During World War II, it was outlawed by the occupying Germans and became a key element of the Resistance. The PCF participated in the provisional government of the Liberation from 1944 to 1947, but for the next 30 years was excluded from government despite consistently winning more than 20 percent of the vote in elections. It fell behind the Socialist Party in the 1970s, though entered government early in François Mitterrand's presidency (1981–1984) and participated in the Plural Left cabinet led by Lionel Jospin (1997–2002).

The history of communism encompasses a wide variety of ideologies and political movements sharing the core principles of common ownership of wealth, economic enterprise, and property. Most modern forms of communism are grounded at least nominally in Marxism, a theory and method conceived by Karl Marx and Friedrich Engels during the 19th century. Marxism subsequently gained a widespread following across much of Europe, and throughout the late 1800s its militant supporters were instrumental in a number of unsuccessful revolutions on that continent. During the same era, there was also a proliferation of communist parties which rejected armed revolution, but embraced the Marxist ideal of collective property and a classless society.

Although Marxist theory suggested that industrial societies were the most suitable places for social revolution (either through peaceful transition or by force of arms), communism was mostly successful in underdeveloped countries with endemic poverty such as the Republic of China. In 1917, the Bolshevik Party seized power during the Russian Revolution and in 1922 created the Soviet Union, the world's first self-declared socialist state. The Bolsheviks thoroughly embraced the concept of proletarian internationalism and world revolution, seeing their struggle as an international rather than a purely regional cause. This was to have a phenomenal impact on the spread of communism during the 20th century as the Soviet Union installed new Marxist–Leninist governments in Central and Eastern Europe following World War II and indirectly backed the ascension of others in the Americas, Asia and Africa. Pivotal to this policy was the Communist International, also known as the Comintern, formed with the perspective of aiding and assisting communist parties around the world and fostering revolution. This was one major cause of tensions during the Cold War as the United States and its military allies equated the global spread of communism with Soviet expansionism by proxy.