Historical Left in the context of 1870s

The Italian Socialist Party (Italian: Partito Socialista Italiano, PSI) was a social democratic and democratic socialist political party in Italy, whose history stretched for longer than a century, making it one of the longest-living parties of the country. Founded in Genoa in 1892, the PSI was from the beginning a big tent of Italy's political left and socialism, ranging from the revolutionary socialism of Andrea Costa to the Marxist-inspired reformist socialism of Filippo Turati and the anarchism of Anna Kuliscioff. Under Turati's leadership, the party was a frequent ally of the Italian Republican Party and the Italian Radical Party at the parliamentary level, while lately entering in dialogue with the remnants of the Historical Left and the Liberal Union during Giovanni Giolitti's governments to ensure representation for the labour movement and the working class. In the 1900s and 1910s, the PSI achieved significant electoral success, becoming Italy's first party in 1919 and during the country's Biennio Rosso in 1921, when it was victim of violent paramilitary activities from the far right, and was not able to move the country in the revolutionary direction it wanted.

A split with what became known as the Communist Party of Italy and the rise to power of former party member and Italian fascist leader Benito Mussolini, who was expelled from the party, class struggle and internationalism in favour of corporatism and ultranationalism, and his National Fascist Party led to the PSI's collapse in the controversial 1924 Italian general election and eventual ban in 1925. This led the party and its remaining leaders to the underground or in exile. The PSI dominated the Italian left until after World War II, when it was eclipsed in status by the Italian Communist Party (PCI). The two parties formed an alliance lasting until 1956 and governed together at the local level, particularly in some big cities and the so-called red regions until the 1990s. The PSI suffered the right-wing split of the Italian Democratic Socialist Party, whose members opposed the alliance with the PCI and favoured joining the Centrism coalition, in 1947 and the left-wing split of the Italian Socialist Party of Proletarian Unity, whose members wanted to continue the cooperation with the PCI, in 1964. Starting from the 1960s, the PSI frequently participated in coalition governments led by Christian Democracy, from the Organic centre-left to the Pentapartito in the 1980s.

The Italian Liberal Party (Italian: Partito Liberale Italiano, PLI) was a liberal political party in Italy.

The PLI, which was heir to the liberal currents of both the Historical Right and the Historical Left, was a minor party after World War II, but also a frequent junior party in government, especially after 1979. It originally represented the right-wing of the Italian liberal movement, while the Italian Republican Party the left-wing. The PLI disintegrated in 1994 following the fallout of the Tangentopoli corruption scandal and was succeeded by several minor parties. The party's most influential leaders were Giovanni Giolitti, Benedetto Croce and Giovanni Malagodi.

The Right group (Italian: Destra), later called Historical Right (Italian: Destra storica) by historians to distinguish it from the right-wing groups of the 20th century, was an Italian conservative parliamentary group during the second half of the 19th century. After 1876, the Historical Right constituted the Constitutional opposition toward the left governments. It originated in the convergence of the most liberal faction of the moderate right and the moderate wing of the democratic left. The party included men from heterogeneous cultural, class, and ideological backgrounds, ranging from British-American individualist liberalism to Neo-Hegelian liberalism as well as liberal-conservatives, from strict secularists to more religiously-oriented reformists. Few prime ministers after 1852 were party men; instead they accepted support where they could find it, and even the governments of the Historical Right during the 1860s included leftists in some capacity.

The Right represented the interests of the Northern bourgeoisie and the Southern aristocracy. Its members were mostly large landowners, industrialists and people related to the military. On economic issues, the Right supported free trade and laissez-faire policies while on social issues it favoured a strong central government, obligatory conscription and during the Cavour era the secular Law of Guarantees, causing Pope Pius IX's Non Expedit policy of abstention. In foreign relations, their goal was the unification of Italy, primarily aiming for an alliance with the British Empire and the French Empire, but sometimes also with the German Empire against Austria-Hungary. In the last decades of its history, the Right was often referred to as Constitutional Opposition.

The Historical Far Left (Italian: Estrema Sinistra Storica), originally known as Far Left (Italian: Estrema Sinistra), Radical Extreme (Italian: Estrema Radicale), simply The Extreme (Italian: L'Estrema), or Party of Democracy (Italian: Partito della Democrazia), was a left-wing parliamentary group and coalition of Radical, Republican and Socialist politicians in Italy during the second half of the 19th century. Formerly known as the extreme wing of the Historical Left before the unification of Italy, it became a separate group when the more moderate branch of the Left accepted the leadership of the House of Savoy to build the new Italian state.

Giovanni Giolitti (Italian pronunciation: [dʒoˈvanni dʒoˈlitti]; 27 October 1842 – 17 July 1928) was an Italian statesman. He was the prime minister of Italy five times between 1892 and 1921. He is the longest-serving democratically elected prime minister in Italian history, and the second-longest serving overall after Benito Mussolini. A prominent leader of the Historical Left and the Liberals, he is widely considered one of the most wealthy, powerful and important politicians in Italian history; due to his dominant position in Italian politics, Giolitti was accused by critics of being an authoritarian leader and a parliamentary dictator.

Giolitti was a master in the political art of trasformismo, the method of making a flexible, centrist coalition of government which isolated the extremes of the Left and the Right in Italian politics after the unification. Under his influence, the Liberals did not develop as a structured party and were a series of informal personal groupings with no formal links to political constituencies. The period between the start of the 20th century and the start of World War I, when he was prime minister and Minister of the Interior from 1901 to 1914, with only brief interruptions, is often referred to as the "Giolittian Era".

The Liberals (Italian: Liberali), also known as Liberal Party (Italian: Partito Liberale, PL) or Giolittian Liberals (Italian: Liberali Giolittiani) from the name of their leader, was a political alliance formed in the first years of the 20th century by the Italian Prime Minister and leader of the Historical Left Giovanni Giolitti. The alliance was formed when the Left and the Right merged in a single centrist and liberal coalition which largely dominated the Italian Parliament.