He was born at Faenza on 8 February 1891, and died on 1 January 1980.
- He began his political life in the Italian Republican Party. In 1921 he joined the Socialist Party and from 1923 to 1925 was the editor of the Socialist paper “Avanti!”.
- In 1926 he was forced to emigrate to France where he became the Secretary of the Italian Socialist Party.
- In 1938 he was the International Socialist Delegate in Spain. After the victory of General Franco he returned to France, but was first imprisoned before being taken to Germany, and then to Italy where he was imprisoned on the island of Ponza. After being liberated on 5 August 1943, he returned to Rome to lead the Italian Socialist Party which had been reunified as the Socialist Party of Proletarian Unity.
- After 8 September 1943 he was one of the political officials of the National Liberation Committee.
- After the Liberation, he took up government responsibilities, becoming Deputy Prime Minister and Minister for the Constituent Assembly in the Parri Government and the 1st De Gasperi Government.
- He was Minister for the Constitution, and on 18 October 1946 Minister for Foreign Affairs in the 2nd De Gasperi Government. From 1963 to 1968 he was Deputy Prime Minister in the 1st, 2nd and 3rd Moro Governments.
- In 1968 he became Minister for Foreign Affairs in the 1st Rumor Government, and it was in this capacity that he announced the Italian Government's decision to recognise the People's Republic of China.