Two-time prime minister Romano Prodi, the centre-left candidate for Italy's presidency, is a former European Commission head of international renown, and the political nemesis of Silvio Berlusconi.
Should he win, the economist nicknamed "Il Professore" would take over the presidency at a delicate time for Italy and would have to resolve a political impasse in the eurozone's third largest economy after inconclusive elections.
Prodi, 73, is best known at home for twice defeating his flamboyant centre-right rival Berlusconi, Italy's richest man and head of a sprawling media empire who has been premier three times and is dogged by legal troubles.
He also boasts getting the country into shape for entry into the eurozone, carrying out economic reforms, cutting spending and imposing a one-off tax.
Prodi basked in international renown as European Commission president from 1999 to 2004, during which time the euro was introduced and 10 new members, many from the former communist bloc, joined the European Union.
Born in 1939 as the eight of nine children, Prodi studied at the London School of Economics, Milan's Catholic University and Stanford before joining the faculty of the University of Bologna as professor of industrial policy.
Praised by supporters for his diplomatic skills and a sobriety contrasting sharply with Berlusconi, he was criticised by others for his professorial manner and nicknamed "the mortadella" after a bland sausage made in Bologna.
Seen as a technocrat lacking charisma and more comfortable on his daily bike ride than on television, Prodi initially won voters round with his avuncular style in 1996, beating Berlusconi at the head of The Olive Tree coalition.
But his first centre-left coalition government fell after two years and five months when he lost the support of the Refoundation Communists, who rejected his efforts to reform the labour market and pensions.
He then went to Brussels, taking over the presidency of the European Commission at a time of crisis and was credited with reviving the body after the previous commission resigned en masse after a fraud and corruption scandal.
Prodi returned to Italy to galvanise a centre-left opposition in disarray and still smarting from Berlusconi's landslide victory in 2001 elections.
After his 2006 election win, he earned new praise for his ability to pull together more than a half-dozen parties into a multi-hued coalition, which stretched from communists to moderate Catholics.
But that same diversity dragged him down, as communists and Greens led opposition to spending cuts while Catholics opposed legislation that would grant legal status to gay couples.
Unperturbed, Prodi cracked down on tax evasion and fought to clean up politics and rid the system of those he felt were acting in their own interests rather than those of the country.
While he was praised by some for his efforts to erase the deficit spending of the Berlusconi years, the centre-right opposition and economists accused him of relying too heavily on tax hikes to check public spending.
In 2008, he was brought down by a vote of no-confidence after the defection of a small party in the coalition and said he would not run for premier again.
The son of an engineer and primary-school teacher left politics and returned to the academic sphere as a professor-at-large at Brown University and a chair for Sino-European dialogue at the China Europe International Business School.
In 2008 he was named head of a United Nations panel aimed at peacekeeping in Africa and in 2012 he became UN special envoy for the Sahel, creating a special fund to help the troubled African region, hit hard by the Mali conflict.
Married with two sons, Prodi began his political career as an industry minister in the government of Giulio Andreotti in 1978-79.
From 1982 to 1989 he was head of the enormous state holding company IRI and helped privatise the debt-ridden behemoth of 450 firms employing 400,000 workers, presaging an all-encompassing effort to cut government fat.
He came under investigation for alleged corruption twice while head of the IRI but both times the case against him was dropped for lack of evidence.