When Mahmoud Ahmadi-Nejad was elected president of Iran a year ago, Donald Rumsfeld, the US defence secretary, admitted he knew little about the "young fellow".
But the blacksmith's son is now one of the most widely recognised political figures in the world, especially as the international face of Iran's nuclear ambitions.
Even his critics concede Mr Ahmadi-Nejad has grown more popular at home and in other Muslim countries despite - or because of - US attempts to demonise him.
Before the dust settled on his landslide victory, US officials had fingered him as one of the militant students who held hostage 52 US embassy staff during the 1979 Islamic Revolution. But the student leaders denied he had been involved, and Washington quietly buried its inquiry. The blunder followed George W. Bush's appeal to Iranians during the election, when the US president's call for a boycott was repeatedly aired by Iranian television as a way to encourage people to vote.
Mr Ahmadi-Nejad won on a slogan of "bringing oil money to the people's sofreh" (dining cloth) and quickly showed an understanding of the Iranian masses lacking not just in Mr Bush but in his own predecessor, the reformist Mohammad Khatami.
Thousands still turn out for his speeches on trips to parts of Iran feeling neglected by central government. "We have to admit he has understood the small towns better than us," says a leading reformist.
But Mr Ahmadi-Nejad has also trail-blazed internationally, beginning with two speeches confronting the western consensus backing Israel.
In October, speaking to students at an anti-zionism conference, he said a "new wave" of Palestinian attacks would "wipe off this disgraceful blot from the face of the Islamic world". In December he suggested Europeans should offer some of their own provinces for a Jewish state.
These speeches raised few eyebrows in Iran but alarmed Europe, the US and many Arab regimes.
"I am 100 per cent sure he didn't expect such a reaction - he used to say such things from ideological conviction," says Nasser Hadian, politics professor at Tehran University and a friend since childhood. "But once he got the reaction, he saw the chance to establish himself among the Muslim masses outside Iran, standing against the US and Israel."
For Ayatollah Ali Khamenei, Iran's supreme leader and most powerful figure, Mr Ahmadi-Nejad has been a mixed blessing.
On one hand, his victory in a lively election boosted Iran's "religious democracy" and showed the egalitarian slogans of the 1979 revolution could still motivate the masses and rewrite a political agenda that had divided Iran between "reformists" and "conservatives".
On the other hand, Mr Ahmad-Nejad, an outsider from a humble background, has shown limited respect for Iran's clerical and political establishment.
His call for class struggle, albeit with an Islamic hue, and an international battle of have-nots against big powers, carries the danger of instability and threatens vested interests developed since the 1979 revolution.
The president was forced to retreat from a promise to oust a "mafia" running the oil ministry, opting for a ministry insider after the parliament vetoed his first three nominations for minister.
Populism has a price, say Mr Ahmadi-Nejad's domestic opponents, who are vocal in the universities, private business, among clerics and in Iran's ethnic minorities.
In Qom, home to Iran's religious elite, grumbles about the president's brand of popular religion boiled over in April as Mr Ahmadi-Nejad told sports authorities to draw up plans to allow women to attend big football matches.
Ayatollah Khamenei intervened, saying it was wrong to decide before consulting the clerics.
Mr Ahmadi-Nejad has shown even less fear of Iran's intellectuals, replacing professors' rights to elect university presidents with appointments by the government. But student protests have been limited and easily curbed by the police.
A more formidable challenge may be brewing among Iran's ethnic minorities, who make up half the 68m population. "There has been unrest among the Azeris, Kurds, Arabs and Baluchis," says Hamid-Reza Jalaipour, a sociology professor at Tehran University and leading reformist. "This is very dangerous and never happened before among all four groups at the same time. The government has mismanaged its response to legitimate complaints."
But the clearest impact of Mr Ahmadi-Nejad's government has been in freezing or reversing the trend towards liberalisation and market reforms under the previous governments of Akbar Hashemi Rafsanjani and Mr Khatanii.
The Tehran stock exchange is stagnant and wary foreign investors are struggling to raise funds as foreign banks limit their exposure amid fears of possible future sanctions. Capital flight to Dubai is unquantified but significant.
In the short term, Mr Ahmadi-Nejad is cushioned by oil and gas income expected to rise to around $50bn (euro40bn, £27.5bn) in the Iranian year ending March 2007, giving him leeway for development projects and to maintain subsidies on bread, energy and petrol.
But shoring up a rentier economy based on oil is a short-term option, says a western diplomat: "Iran is surviving, but the oil revenue is not being invested productively. Can this go on for ever? History says no. How long can it last? History doesn't tell us."
Neither is it clear history will remember Mr Ahmadi-Nejad as a lasting influence on Iran's nuclear policy for Iran's nuclear policy. He remains Iran's public face in defending its "rights" and senior officials feel the more assertive policy adopted last summer, even before he took office, has yielded results.
But at the same time, they say Iran is ready for a compromise that Mr Ahmadi-Nejad would have to accept - whether he liked it or not.
"Ayatollah Khamenei does not want a crisis," a regime insider told the FT. "And the Americans know it's Ayatollah Khamenei they have to talk to, not Mr Ahmadi Nejad "
Under syndication arrangement with FE