Carlo Cafiero was born in Barletta, in the Apulia region of southern Italy, into a rich, land-owning family. His father was member of the Carboneria in 1821, one of his brothers and a brother-in-law were deputies, while Carlo Cafiero was always considered the 'black sheep' of the family.
In 1864, he moved to Naples, where he got a degree in law. He then went to Florence to embark on a diplomatic career. Here, he first came into contact with atheist ideas, through the Rationalist movement. At the beginning of 1870 he was in Paris as guest of the painter Giuseppe De Nittis, a fellow townsman who described him as a "beautiful young man, fascinating to women". He then went to London, where he matured, renouncing his diplomatic career, wealth and family to join the revolution and socialism. It seems that hearing the enthralling rally of a shoemaker caused Cafiero to become conscious of the pitiful conditions of the working class. In London, Cafiero made contact with Marx and Engels.
He joined the International Workingmen's Association and was charged with winning Italy over to Marx’s ideology, in a country where workers were under the strong influence of the Republicanism of Giuseppe Mazzini or in some places the Anarchism of Mikhail Bakunin. He re-formed the old branch of the International in Naples, with the help of the young Errico Malatesta. There, during an assembly, he was imprisoned for the first time.
Cafiero spent over a year in Italy as a representative of Marx and Engels to hinder the influence of anarchism. However, thanks to the contact he had had with Giuseppe Fanelli, he passed over to the other side of the barricade, siding with Bakunin and his Italian followers. In early 1872 came the first issue of the newspaper La Campana and Cafiero wrote for, and donated for its publication. In the same year he met Bakunin in Locarno (Switzerland) spending a month with him, discussing Bakunin’s ideas and objections to what Bakunin perceived as Marx and Engels’ authoritarianism, winning Cafiero in the end to his cause. In the summer of 1873, with the help of Cafiero, an old project was realised: to create an international center for the revolution in Italy and the world. Cafiero, selling all his inherited lands, bought a farm in Switzerland where Bakunin could live. This center was called La Baronata, and it would also be a safe shelter for revolutionaries persecuted by their respective governments. In 1875 Cafiero went to Milan and joined the editorial staff of the first socialist daily paper, La Plebe, edited by Enrico Bignami. In April 1877, Cafiero, Malatesta, Ceccarelli, the Russian Stepniak and 30 other comrades began an insurrection in the province of Benevento. They took the village of Letino without a struggle where they were greeted with great enthusiasm. Arms and expropriated goods were distributed amongst the people, tax money was returned and official documents destroyed. Cafiero, in dialect, explained the ideas of anarchism, freedom, justice and the new society without the State, without masters, servants, soldiers and owners. His proclamations even convinced the parish priest, who explained to his parishioners that the Internationalists were 'the true apostles sent by the Lord'. The following day the village of Gallo was taken in a similar fashion. Unfortunately, as they were leaving Gallo the Internationalists were surprised and surrounded by government troops and all were arrested. Held in prison for over a year before being brought to trial, all the accused were eventually acquitted in August 1878.
During his imprisonment his contacts with the International never ceased and Cafiero wrote his best-known work: A Compendium of Das Kapital, published in 1879 in Milan by the publishers of La Plebe. The work was appreciated and praised even by Marx who found it superior to other similar works. The Compendium was written in order to bring the theory of Capital to students, educated workmen and small proprietors. In 1878, Cafiero, unable to return to Italy because of Giovanni Passannante's attempt who brought a strong repression against republicans and internationalists, was living in Marseilles, working as a cook and docker. In October he was arrested along with Malatesta, then released and deported from France. He went to Switzerland, where he met Peter Kropotkin and, with the collaboration of Élisée Reclus, promoted the publication of the Bakunin's essay God and the State. Andrea Costa, who had deserted the anarchist camp by passing over to legalitarian, parliamentary Socialism, disappointed Cafiero who described him as "an apostate, a renegade of the revolutionary faith and the people". After being arrested and soon released, in 1881 Cafiero went to London, where he remained for a long time. There he was the victim of a strange illness which was accompanied by feelings of persecution; he saw spies everywhere and was frightened by the telephone, which had just appeared in the world. In March 1882 he returned to Italy, expressing a will to take part in the imminent electoral campaign. On April 5 he was arrested without any charge but, on May 2, while imprisoned, he fell victim to a strong mental crisis and attempted to kill himself. The scandal of a crazed man, imprisoned without reason, exploded and Cafiero was released but given a choice of living in Barletta, his home town, or exile to Switzerland.
Emaciated and feverish, he chose exile in Chiasso, where he again attempted suicide. Emilio Bellerio took Cafiero to his house in Locarno and Errico Malatesta wrote about him: "though his mind is ill, his heart is still healthy...". In February 1883 Cafiero left for Florence, where he was met by a friend. He immediately headed for Fiesole, took rooms in an inn but then immediately fled into the woods, where he was later found half-naked. After being aided by a doctor and the police he was transferred to the San Bonifacio psychiatric hospital in Florence. Olimpia Kutusoff, Cafiero's wife, returned from Russia in September 1883 to look after him at the Imola psychiatric hospital, where he had been transferred. Olimpia left him after one and a half years because Cafiero was violent with her during his moments of crisis. Carlo expressed the will to return to Barletta, where he arrived in the second half of ’89. However, his brothers turned him away but, after living some time in a hotel, he was taken in by his brother Pietrantonio. Cafiero's mental conditions improved, but one day, returning home, he saw a group of peasants eating a piece of black, hard bread which revived his revolutionary spirit and he entered his house screaming against his family. In 1891, following another crisis, Carlo Cafiero was confined in the psychiatric hospital in Nocera Inferiore, where he died on Sunday 17 July 1892 of tuberculosis at the age of 45.
"My friends, let us hurry on the Revolution as quickly as we can, since, as you see, our enemies are letting us die like this - in prison or in exile, or crazed with sorrow" - Spoken by Cafiero at Giuseppe Fanelli’s funeral.
"The common wealth being scattered right across the planet, while belonging to the whole of humanity, those who happen to be within reach of that wealth and in a position to make use of it will utilise it in common. . . . As part of humanity, they will exercise here, in fact and directly, their rights over a portion of mankind's wealth. But should an inhabitant of Peking visit this country, he would enjoy the same rights as the rest, in common with the others, he would enjoy all the wealth of the country, just as he would have in Peking." [From Anarchy and Communism, a report given by Cafiero to the Congress of the Jura Federation of the IWMA in 1880. In Daniel Guérin, No Gods, No Masters, Book 1, p. 250]
"Carlo was first of all great for his inner nature, for the affect treasure, for the ingenuousness of his faith. These memories must not be lost, even today that there is the need to elevate the moral level of anarchists, who must react against the egoism and brutality that invade us, to return to unselfishness, to the sacrificial spirit, to the sentiment of love, of which Carlo was such a splendid example". - Errico Malatesta, in a letter to Serafino Mazzotti.