anticlerical social-reform party. Although it had only a small following in the years after World War II, its position in the centre of the Italian political spectrum enabled it to take part in many coalition governments.

The party dates back to the 19th century, when radicals fought for a unified Italy under a republican form of government; the PRI was formally founded in 1895. Suppressed during Benito Mussolini (Mussolini, Benito)'s fascist era, it reemerged in 1943. After World War II, the PRI refused to participate in government until Italians voted against monarchical government. From 1947 to 1953, the PRI participated in the four-party “centre” governments. Important Republican politicians, notably Ugo La Malfa, played central roles in Italian politics at this time. The party withdrew from government in 1953 and did not return until February 1963, when the dominant centre party, the Christian Democratic Party, joined Italy's two socialist parties and the PRI in a centre-left coalition. The PRI usually remained in government thereafter, and a PRI leader, Giovanni Spadolini, was premier in 1981 and 1982.

The Republicans were among many parties caught up in the corruption scandals that rocked Italy after 1992. The PRI remained a very minor part of the centre-left Olive Tree alliance through the 1990s.