The Italian Communist Party (Italian: Partito Comunista Italiano, or PCI) emerged as the Communist Party of Italy (Partito Comunista d'Italia) by seceding from the Italian Socialist Party (PSI) at their congress on 21 January 1921 at Livorno. Amadeo Bordiga and Antonio Gramsci led the split. Outlawed during the Fascist regime, the party reformed in Italy after World War II and became the strongest force among the Italian left-wing parties, attracting the support of about a third of the voters during the 1970s. At the time, it was the biggest communist party in the West (1.7 million members and 34.4% votes in 1976).
In 1991 the PCI disbanded to form the Democratic Party of the Left (Partito Democratico della Sinistra or PDS), with membership in the Socialist International. More radical members of the party, led by Armando Cossutta, left the party to form the Communist Refoundation Party (Partito della Rifondazione Comunista, or PRC). In 1998 the PDS, with several smaller parties, (the Liberal Socialists or Laburisti, the Christian Socialists or Cristiano Sociali, the United Communists or Comunisti Unitari (right-wing split of the PRC), the Left Republicans or Sinistra Repubblicana, and the Social Democratic Trade Unionists or Riformatori per l'Europa), co-founded the Democrats of the Left party ("Democratici di Sinistra", or DS). Later in the same year the a faction led by Armando Cossutta left the PRC to form the Party of Italian Communists (Partito dei Comunisti Italiani, or PdCI).
In 1926, the Fascist government of Benito Mussolini outlawed the PCI. Although forced underground, the PCI maintained a clandestine presence within Italy during the years of the Fascist regime. Many of its leaders were also active in exile. During its first year as a banned party, Antonio Gramsci defeated the party's left wing, led by Amadeo Bordiga. Gramsci replaced Bordiga's leadership at a conference in Lyon, and issued a manifesto expressing the programmatic basis of the party. However, Gramsci soon found himself jailed by Mussolini's regime, and the leadership of the party passed to Palmiro Togliatti. Togliatti would lead the party until it emerged from suppression in 1944 and relaunched itself as the Italian Communist Party.
The party played a major role during the national liberation (Resistenza) and in the April of 1944 after the Svolta di Salerno (Salerno's turn ), Togliatti agreed to cooperate with the the king so the communists took part in every government during the national liberation and constitutional period from June 1944 to May 1947. The communists' contribution to the new Italian democratic constitution was decisive. In the first general elections of 1948 the party joined the PSI in the Popular Democratic Front but was defeated by the Christian Democracy party. The party gained considerable electoral success during the following years and occasionally supplied external support to center-left governments, although it never directly joined a government. It successfully lobbied Fiat to set up the AvtoVAZ (Lada) car factory in the Soviet Union. The party did best in Central Italy, particularly in Tuscany, Emilia Romagna and Umbria, where it regularly won the local administrative elections, and in some of the industrialized cities of Northern Italy.
The Soviet Union's brutal suppression of the Hungarian Revolution of 1956 created a split within the PCI. The party leadership, including Palmiro Togliatti and Giorgio Napolitano (who in 2006 became President of the Italian Republic), regarded the Hungarian insurgents as counter-revolutionaries, as reported at the time in l'Unità, the official PCI newspaper. However Giuseppe Di Vittorio , chief of the communist trade union CGIL, repudiated the leadership position, as did prominent party member Antonio Giolitti and Italian Socialist Party national secretary Pietro Nenni, a close ally of the PCI. Napolitano later hinted at doubts over the propriety of his decision. He would eventually write in From the Communist Party to European Socialism. A political autobiography (Dal Pci al socialismo europeo. Un'autobiografia politica) that he regretted his justification of the Soviet intervention, but quieted his concerns at the time for the sake of party unity and the international leadership of Soviet communism. Giolitti and Nenni went on to split with the PCI over this issue. Napolitano became a leading member of the miglioristi faction within the PCI, which promoted a social-democratic direction in party policy.
In the mid 1960s the U.S. State Department estimated the party membership to be approximately 1 350 000 (4.2% of the working age population, the proportionally largest communist party in the capitalist world at the time, and the largest party at all in whole western Europe with the German SPD).
Declassified information from Soviet archives confirms that the PCI relied on Soviet financial assistance, more so than any other Communist party supported by Moscow. The party received perhaps as much as $60 million from the end of World War II until the PCI’s break with Moscow in the early 1980s. The party used these funds mainly for organizational purposes. According to the former KGB archivist Vasili Mitrokhin, after the Athens Colonel Coup in April of 1967, Longo and other PCI leaders became alarmed at the possibility of a coup in Italy. These fears were not completely unfounded, as there had been two attempted coups in Italy, Piano Solo in 1964 and Golpe Borghese in 1970, by neo-fascist and military groups. The PCI’s Giorgio Amendola formally requested Soviet assistance to prepare the party in case of such an event. The KGB drew up and implemented a plan to provide the PCI with its own intelligence and clandestine signal corps. From 1967 through 1973, PCI members were sent to East Germany and Moscow to receive training in clandestine warfare and information gathering techniques by both the Stasi and the KGB. Shortly before the May 1972 elections, Longo personally wrote to Leonid Brezhnev asking for and receiving an additional $5.7 million in funding. This was on top of the $3.5 million that the Soviet Union gave the PCI in 1971. The Soviets also provided additional funding through the use of front companies providing generous contracts to PCI members.
In 1969, Enrico Berlinguer, PCI deputy national secretary and later secretary general, took part in the international conference of the Communist parties in Moscow, where his delegation disagreed with the "official" political line, and refused to support the final report. Unexpectedly to his hosts, his speech challenged the Communist leadership in Moscow. He refused to "excommunicate" the Chinese communists, and directly told Leonid Brezhnev that the invasion of Czechoslovakia by the Warsaw Pact countries (which he called the "tragedy in Prague") had made clear the considerable differences within the Communist movement on fundamental questions such as national sovereignty, socialist democracy, and the freedom of culture. At the time the PCI was the largest Communist Party in a capitalist state, garnering 34.4% of the vote in the 1976 general election.
Relationships between the PCI and the Soviet Union gradually fell apart as the party moved away from Soviet obedience and Marxist-Leninist orthodoxy in the 1970s and 1980s, as the PCI definitively embracing eurocommunism and the Socialist International. The PCI sought a collaboration with Socialist and Christian Democracy parties (the historic compromise). However, Christian Democratic party leader Aldo Moro's kidnapping and murder by the Red Brigades in May 1978 put an end to any hopes of such a compromise.
During the "anni di piombo" the PCI strongly opposed the terrorism and the Red Brigades, who, in turn, murdered or wounded many PCI members or trade unionists close to the PCI. According to Mitrokhin, the party asked the Soviets to pressure the Czechoslovakian State Security (StB) to withdraw their support to the group, which Moscow was unable or unwilling to do. This as well as the Soviet invasion of Afghanistan led to a complete break with Moscow in 1979. In 1980, the PCI refused to participate in the international conference of Communist parties in Paris although cash payments to the PCI continued until 1984.
In 1991 the Italian Communist Party split into the Democratic Party of the Left (PDS), led by Achille Occhetto, and the Communist Refoundation Party (Partito della Rifondazione Comunista), headed by Armando Cossutta. Occhetto, leader of the PCI since 1988, stunned the party faithfully assembled in a working-class section of Bologna with a speech heralding the end of communism, a move now referred to in Italian politics as the Bolognina. The collapse of the communist governments in the Soviet Union and Eastern Europe had convinced Occhetto that the era of eurocommunism was over, and he transformed the PCI into a progressive left-wing party, the PDS. Cossutta and a third of the PCI membership refused to join the PDS, and instead founded the Communist Refoundation Party.