The Centre-left appears in Italy for the first time in 1850 when the Historical Right leader Camillo Benso, Count of Cavour and the Historical Left one, Urbano Rattazzi, joined a coalition known as Connubio. The other main political bloc is the Centre-right. Important leaders of the Italian centre-left were Aldo Moro, Amintore Fanfani, Enrico Berlinguer, Romano Prodi, Matteo Renzi, Giorgio Napolitano, Massimo D'Alema, Giuliano Amato, Walter Veltroni, Enrico Letta, Francesco Rutelli and Pier Luigi Bersani.
In 1962 the Christian Democracy (DC) leader Amintore Fanfani formed a cabinet with members of the Italian Social Democratic Party (PSDI) and the Italian Republican Party (PRI); it is considered the beginning of the Organic Centre-left.
On 4 December 1963, Aldo Moro formed the first government with the support of the Italian Socialist Party (PSI). Prominent socialist politicians, such as Pietro Nenni and Antonio Giolitti, were appointed ministers.