Short answers, pulled from the story.
Enrico De Nicola was an Italian jurist, journalist, politician, and statesman born in Naples on the 9th of November 1877. He served as Italy's first President of the Italian Republic when the new constitution took effect on the 1st of January 1948, and before that as provisional head of state from 1946 to 1948.
The Constituent Assembly elected De Nicola Provisional Head of State on the 28th of June 1946, with roughly 80% of the votes at the first round of voting. He was chosen after the Constitutional Referendum brought republicans to power and King Umberto II was exiled.
Giulio Andreotti recalled that De Nicola, described as a man of great modesty, was uncertain whether to accept the nomination and changed his mind repeatedly despite insistence from all major political leaders. The journalist Manlio Lupinacci published an appeal in Il Giornale d'Italia urging him to decide.
De Nicola graduated from the University of Naples in 1896 and became well known as a penal lawyer. He was elected a Liberal deputy in 1909, served as Under-Secretary of State for the Colonies in 1913-1914 and Under-Secretary of State for the Treasury in 1919, and was elected speaker of the Chamber of Deputies in 1920.
De Nicola resigned on the 25th of June 1947, citing health reasons. The Constituent Assembly re-elected him the following day, interpreting his resignation as a sign of nobility and humility rather than a reason to seek a replacement.
After Luigi Einaudi succeeded him as president following the May 1948 election, De Nicola became a senator for life as a former head of state. He was subsequently elected President of the Senate and later President of the Constitutional Court. He died at Torre del Greco on the 1st of October 1959.