He was born from the liaison of Paolina Bergamaschi, a nurse, with Stefano Bissolati, a priest who left the Church in 1859, at age 37, and later became director of Cremona's city library and a noted scholar. At birth the child was named Leonida Bergamaschi; his name was changed at age 18, when Stefano Bissolati legally adopted him (after marrying Paolina in 1868, five years after she had become a widow). With this family background, Leonida Bissolati naturally was a leftist already as a student at the University of Bologna, where he earned his law degree at age 20. Returning to Cremona, he practiced law as an attorney and published many articles in journals and newspapers. In 1876 he was elected to the City Council of Cremona, at first in the ranks of the Radicals, then gradually moving closer to the Socialists. He served for 18 years, notably by being in charge of Public Education. He married Ginevra Coggi, who soon fell chronically illand died in 1894; later, his soulmate and companion was Carolina Cassola, whom he eventually married in 1913.
From 1889 to 1895 he organized peasant demonstrations and the social struggle for better living conditions in the countryside. In 1889 he founded "L'eco del popolo" (The Echo of the People), which subsequently became the local organ in Cremona of the Italian Socialist Party (PSI). He also published a partial translation of the Communist Manifesto of Marx and Engels. In 1896 he became director of the "Avanti!" (Forward!), the official organ of the PSI, relinquishing this post in 1903, to resume it later from 1908 to 1910. In 1897 he was elected to the Chamber of Deputies of the Italian Parliament for the college of Cremona. His refusal to oppose the war on Turkey for the conquest of Libya triggered his resignation as socialist Member of Parliament in February 1912; five months later he was expelled from the PSI. He promptly went on to found the Italian Reformist Socialist Party (Partito Socialista Riformista Italiano), with Bonomi and Cabrini.
Bissolati strongly advocated Italy's entry into World War I on the side of the Triple Entente, while his former socialist friends favored neutrality. He volunteered for the front and served with distinction, receiving a medal. Back in Rome, he served in two successive Italian Governments (those headed by Boselli and Orlando). He was responsible for supplying troops and keeping in touch with the generals. At the end of the war, he supported the League of Nations and Woodrow Wilson's principle of self-determination in the settling of the new national borders. This infuriated the nationalists, bent on annexing to Italy sizeable areas inhabited by Germans and Slavs in the Northeast. Attacked from all sides, he resigned from the government and withdrew from politics in December 1918, although subsequently met with Woodrow Wilson and urged that Italy not be given Fiume or the Dalmatian Coast.
He died in Rome of a post-operative infection.
- Alfassio Grimaldi, Ugoberto; Gherardo Bozzetti (1983). Bissolati (in Italian). Milan,: Rizzoli Press.
- Chisholm, Hugh, ed. (1922). "Bissolati-Bergamaschi, Leonida". Encyclopædia Britannica (12th ed.). London & New York.