His electoral slogan was "moderation and wisdom" and, since he became the President of Iran in August, that is precisely what he has practised.
But cleric Hassan Rouhani, the Iranian leader who recently broke decades of unremitting hostility by concluding a historic nuclear agreement with the West, continues to be an enigma.
To many, he is a symbol of a new Iran, a confident country determined to end its international isolation.
But to his critics he is, as Israeli Prime Minister Benjamin Netanyahu dismissively put it, "a wolf in sheep's clothing", someone who hoodwinks opponents by pretending to be a moderate.
The reality is probably somewhere in between; the one feature which most stands out about MrRouhani's career is his ability to navigate the shark-infested waters of Iranian politics by playing more than one role at the same time.
Born 65 years ago in the same dusty province of Semnan in northern Iran as predecessor Mahmoud Ahmadinejad, whom he replaced in office this year, Mr Rouhani's initial background offered no clues that he was destined for higher things: His family sold carpets and spices, the traditional trade of the provincial merchant class.
But it quickly became evident that he was both studious and exceptionally bright: At school, his teachers used to let him take charge of some of the classes.
His passion for religion came early, and was profound: It inspired him to change his family name from the original Fereydun to Rouhani which, roughly translated, means "spiritual man". But his love of the faith was never narrow:
He was interested in the flexibility of Islam, in what it embraces or tolerates, rather than what it rejects or bans.
A degree in religious education followed naturally. And so did Mr Rouhani's opposition to the Shah and his dynasty. By the early 1970s, he was already a marked man and had to leave the country, joining the Ayatollah Khomeini, who also opposed the Shah, in exile.
He returned with the Ayatollah after the fall of the Shah and specialised in what he does best to this day: Picking up the pieces after disasters created by others. He revived Iran's army, which was in tatters after the revolution.
In the process, Mr Rouhani also gained a deep knowledge of Iran's military and security services which has served him well.
Still, he rejected an offer to head Iran's intelligence agencies, largely because he realised that this meant entering a cesspit.
And he left Iran altogether during the 1990s to complete a doctorate thesis at a British polytechnic. Both decisions were a stroke of genius, since they not only ensured that Mr Rouhani survived unscathed, but also guaranteed that he remained on good terms with all of Iran's political factions.
And ambiguity continued to be his personal hallmark. He currently promises to promote civil rights, by "restoring dignity to the nation" as he puts it.
But, as secretary of Iran's National Security Council in 1999, he led the bloody repression of student demonstrations by ordering paramilitary forces to "crush mercilessly and monumentally these opportunist elements".
In 2003, Mr Rouhani negotiated a deal to freeze his country's nuclear programme, which he claimed that Teheran implemented "in good faith".
Yet he also subsequently boasted that "while we were talking with the Europeans in Teheran, we were installing equipment in parts of the nuclear conversion facility in Isfahan".
Not much is known about Mr Rouhani's private life either. When he reached the age of 21, his mother - who is still alive and influential - arranged for him to marry a 14-year-old girl, who has seldom been seen since.
Mr Rouhani was the only candidate in Iran's latest presidential election to avoid parading his family during the campaign. He also suffered a personal tragedy when his son died in London in the 1990s; some say that he committed suicide, while others claim that he was assassinated, but the Iranian President invariably refuses to even mention this topic.
But behind the austere image may lurk a very different personality.
"A nice smile plays on his lips," said Mr Jack Straw, who used to deal frequently with the Iranian when he was British Foreign Secretary in the mid-2000s.
And if a Muslim cleric were ever to make it to the pages of Vogue magazine, it is also likely to be Mr Rouhani, always impeccably turned out in well-cut dark robes and snowy turban.
For the moment, his reputation is soaring: The "diplomatic sheikh", as he is known at home, has delivered a nuclear deal which eluded all his predecessors.
But this was the easy part. For ahead lie much thornier negotiations about the final status of Iran's nuclear programme, as well as one problem in which he has no experience: Fixing his country's economy.
He may ultimately succeed on both counts. Still, he can do so only by taking risks, by gambling on his popularity in order to shore up his domestic policy credentials.
It will be a bet like no other for the once diplomat-scholar who rose to the top by being cautious and elusive.
jonathan.eyal@gmail.com
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