Italy's previous president, Giorgio Napolitano, died in hospital in Rome on Friday.
Condolences poured in from Italian Prime Minister Giorgia Meloni's office, other politicians and the Vatican.
"I gratefully recall the personal meetings I had with him, during which I appreciated his humanity and foresight in making important choices with rectitude, especially at delicate times for the life of the country," Pope Francis wrote in a telegram of condolences to Napolitano's wife Clio Bittoni.
Napolitano, who served as president from 2006-2015, is the only person to be re-elected to the post.
Debt crisis stretched Italy to the brink
His time in office coincided with the eurozone's sovereign debt crisis in the aftermath of the 2008 financial crash, which hit Italy particularly hard. He worked with no fewer than five different prime ministers during less than a decade as president.
The change of governments that Napolitano was best known for, though, was when Silvio Berlusconi resigned late in 2011 after explicit encouragement from the president. Napolitano then established a technocrat government led by former European Commissioner Mario Monti.
The change, at the height of the debt crisis and amid severe pressure from the EU and countries like Germany, put the ceremonial role of the Italian presidency into some question. He earned the nickname "King Giorgio," spoken fondly in some circles and in others less so.
One biography with a comparatively kind view of the actions he took to try to stabilize both Italy's economy and possibly Europe's as a whole dubbed Napolitano "the Communist who saved Italy."
Berlusconi, who initially accepted the play, later accused Napolitano of orchestrating a "soft coup d'etat."
Napolitano was also known for his close ties to the German former Pope Benedict XVI, and was one of few people to have received advanced warning of his shock decision to step down in 2013, later in the president's tenure.
Napoli by name...
Born in Naples in 1925, Napolitano began his political career by joining the Italian Communist Party in 1945. He was first elected to Italy's Chamber of Deputies in 1953 and remained undefeated in every re-election campaign from then until 1996.
After the dissolution of the Communist Party, Napolitano, like many others from the PCI, joined the Democratic Party of the Left.
After serving as president of the Chamber of Deputies in the early 1990s, Napolitano became Minister of the Interior under center-left Prime Minister Romano Prodi from 1996-1998. He was elected to the European Parliament as a member of the Party of European Socialists in 1999, where he served until 2004.
Napolitano remained politically active after his presidency. His successor, Sergio Mattarella, is still in the post and is already the second-longest serving president in Italy's modern history.
He is survived by his wife Clio and two sons, Giovanni and Giulio.