Nenni, Pietro(pyĕ`trō nĕn`nē), 1891–1980, Italian journalist and political leader. He was imprisoned in 1911 for his participation in the protest movement against the Italo-Turkish war in Libya. He joined the Socialist party in 1921 and subsequently became Paris correspondent and later editor of the Socialist party newspaper Avanti. As an opponent of Fascism, he was forced to emigrate to France in 1926. He fought against the fascists in Spain during the Spanish civil war. In 1943 he was arrested by the Germans in Vichy France and then imprisoned in Italy. Released in Aug., 1943, he began to reorganize the Italian Socialist party, becoming its secretary-general in 1944. He precipitated a split in the party by entering into a political alliance with the Communists in 1947. This alliance was renounced in 1962, in the "opening to the left" of the Christian Democrats. Nenni served in several postwar cabinets, as deputy prime minister or as minister of foreign affairs. In 1971 he ran unsuccessfully for president of Italy.
Born Feb. 9, 1891, in Faenza, Ravenna. Figure in the Italian and international socialist movement. Journalist by profession.
Nenni began his political career as a member of the Republican Party. In 1911 he became secretary of the Chamber of Labor in Forli. For organizing protest strikes against Italian aggression in Libya (1911–12), he was sentenced to a year in prison. In June 1914 he was one of the leaders of Red Week, a nationwide general strike during which there was fighting on the barricades in a number of Italian cities. In 1915 he supported Italy’s entry into World War I and volunteered for the army.
In 1921, Nenni joined the Italian Socialist Party (ISP) and in 1922–23 was editor of Avanti! (Forward!). He emigrated to France in 1926. From 1931 to 1939 he was general secretary of the ISP and a member of the executive committee of the Second International. As fascism spread in Europe, Nenni advocated united action with the Communists; in 1934, on behalf of the ISP, he signed a pact with the Italian Communist Party calling for such action. From 1936 to 1938, during the antifascist war in Spain (1936–39), Nenni represented the Second International in Spain and served as a commissar in the international brigades. He was later interned in France, arrested by the Gestapo, handed over to the Italian Fascist authorities, and imprisoned until August 1943.
In 1943–44 and from 1949 to 1963, Nenni served as general secretary of the ISP. In 1945–46 he was vice-premier and minister for the Constituent Assembly; in 1946–47 he was minister of foreign affairs. He has been a deputy to every session of the Italian parliament since 1946 and in 1970 became a senator for life. Until the mid-1950’s, Nenni led the left wing of the ISP. From 1950 to 1955 he was a vice-president of the World Peace Council. In 1952 he was awarded the International Lenin Prize for Strengthening Peace Between Nations.
Nenni moved sharply to the right late in the 1950’s, heading the “autonomist” faction in the ISP and taking anti-Communist positions. He came out in favor of unification between the ISP and the Social Democrats, which was achieved in 1966. From 1963 to 1968 he was deputy premier in the left-center government of A. Moro. Between October 1966 and July 1969, Nenni was chairman of the Unified Socialist Party, which in 1968 adopted the name ISP-Italian Section of the Socialist International. After a party split in 1969 and the departure of the right wing, Nenni remained in the ISP and took an antifascist stance. In 1969 he was elected vice-chairman of the Socialist International and in 1973 chairman of the ISP.