Hassan Rowhani, the portly cleric who has set the Iran's presidential election alight, was never meant to be the standard-bearer of the country's battered reform movement.
In a field dominated by hardliners, Mr Rowhani, 64, was seen as a moderate conservative member of Iran's political establishment.
As secretary of the National Security Council, first during the presidency of Akbar Hashemi Rafsanjani, and then while the reformist, Mohammad Khatami was president, he was ultimately answerable to Ayatollah Ali Khamenei, Iran's supreme leader and constitutionally most powerful figure.
In that post, he served as Iran's chief nuclear negotiator between 2003 and 2005 after an exiled opposition group revealed the existence of the Islamic regime's uranium enrichment programme.
Negotiating with Jack Straw, then Britain's Foreign Secretary, and other European diplomats, Mr Rowhani agreed to a temporary suspension of Iran's enrichment activities – after being given the go ahead by Ayatollah Khamenei. Mr Straw has paid tribute to Mr Rowhani's negotiating skill as "extremely professional".
He subsequently resigned soon after President Mahmoud Ahmadinejad took office in 2005, after hardliners attacked his negotiating stance as too conciliatory.
After being approved as a candidate for the 2013 election by the powerful guardian council, Mr Rowhani looked like a relative liberal compared to his more hawkish opponents. He attracted the support of reform-minded voters with his call for an end to the repressive "security atmosphere" and a pledge to allow greater personal freedom. He has vowed to seek an improvement in Iran's relations with the West.
His election rallies are reported to have attracted mass turnouts, particularly after he earned the endorsements this week of Mr Khatami and Mr Rafsanjani – who have more established credentials as representatives of Iran's liberal-leaning middle classes.
Some of his campaign workers were detained after a rally two weeks at which supporters were heard chanting slogans in support of Mir Hossein Mousavi and Mehdi Karroubi, reformist candidates in the fraud-tainted 2009 elections, who are now under house arrest.
