During summer 1964 the so-called Piano Solo prepared by general Giovanni De Lorenzo was conceived to make a coup d'état and overthrow the first centre-left government led by Aldo Moro.

The coup was stopped before taking place, as the Italian Socialist Party agreed to reduce its more radical reformist claims.

However, on 7 August 1964, during a heated discussion with the Prime Minister Moro and the leader of the Italian Democratic Socialist Party Giuseppe Saragat, President Antonio Segni suffered a serious cerebral hemorrhage in his office at the Quirinal Palace.

The official candidate of Christian Democracy was the former president of the Chamber of Deputies Giovanni Leone, whose candidacy was immediately contrasted by the former Prime Minister Amintore Fanfani, preferred by the left-wing faction of the party.

On the twenty-first ballot and after almost two weeks of voting, Giuseppe Saragat was finally elected President by a large margin and sworn in on 29 December 1964.