First International in the context of Geneva Congress (1866)

"The Civil War in France" (German: Der Bürgerkrieg in Frankreich) is a pamphlet written and first published in 1871 by Karl Marx as an official statement of the General Council of the First International on the Franco-Prussian War and on the character and significance of the struggle of the Communards in the Paris Commune.

The Socialist International, commonly known as the Second International, was a political international of socialist and labour parties formed in Paris on 14 July 1889. At a time of growing industrial working-class movements and the expansion of suffrage, it brought together autonomous national parties into a loose international federation. It continued the work of the First International (1864–1876), from which it inherited both the legacy of Karl Marx and the conflict with anarchists. The organization was dominated by the powerful Social Democratic Party of Germany (SPD), whose organizational and theoretical leadership heavily influenced the other member parties.

The International established the annual celebration of International Workers' Day on 1 May and popularised the demand for an eight-hour day. Its early congresses were preoccupied with expelling anarchists and defining its mission as one based on parliamentary political action. After 1900, the International was increasingly confronted with the internal divisions of the socialist movement, particularly the rise of revisionism in Germany and the debate over socialist participation in "bourgeois" governments, sparked by the Millerand affair in France. The 1904 Amsterdam Congress, which saw a major debate between French socialist Jean Jaurès and German leader August Bebel, condemned revisionism and ministerialism, marking the highest point in the influence of the International.

Antimilitarism (also spelt anti-militarism) is a doctrine that opposes war, relying heavily on a critical theory of imperialism and was an explicit goal of the First and Second International. Whereas pacifism is the doctrine that disputes (especially between countries) should be settled without recourse to violence, Paul B. Miller defines anti-militarism as "ideology and activities...aimed at reducing the civil power of the military and ultimately, preventing international war". Cynthia Cockburn defines an anti-militarist movement as one opposed to "military rule, high military expenditure or the imposition of foreign bases in their country". Martin Ceadel points out that anti-militarism is sometimes equated with pacificism—general opposition to war or violence, except in cases where force is deemed necessary to advance the cause of peace.

Italian anarchism as a movement began primarily from the influence of Mikhail Bakunin, Giuseppe Fanelli, Carlo Cafiero, and Errico Malatesta. Rooted in collectivist anarchism and social or socialist anarchism, it expanded to include illegalist individualist anarchism, mutualism, anarcho-syndicalism, and especially anarcho-communism. In fact, anarcho-communism first fully formed into its modern strain within the Italian section of the First International. Italian anarchism and Italian anarchists participated in the biennio rosso and survived Italian Fascism, with Italian anarchists significantly contributing to the Italian Resistance Movement. Platformism and insurrectionary anarchism have long been particularly common in Italian anarchism and continue to influence the movement today. The synthesist Italian Anarchist Federation and insurrectionary Informal Anarchist Federation appeared after the war, and autonomismo and operaismo especially influenced Italian anarchism in the second half of the 20th century.

William Batchelder Greene (April 4, 1819 – May 30, 1878) was an American individualist anarchist, Unitarian minister, soldier, mutualist, promoter of free banking in the United States, and member of the First International.