TEHRAN, Iran — His followers have begun calling him "the Gandhi of Iran." His image is carried aloft in the vast opposition demonstrations that have shaken Iran in recent days, his name chanted in the streets.
Mir Hossein Mousavi has become the public face of the movement, the man the protesters consider the true winner of the disputed presidential election.
But he is in some ways an accidental leader, a moderate figure anointed at the last minute to represent a popular upwelling against the presidency of Mahmoud Ahmadinejad. He is far from being a liberal in the Western sense, and it is not yet clear how far he will be willing to go in defending the broad democratic hopes he has come to embody.
Mousavi, 67, is an insider who has moved toward opposition, and his motives for doing so remain murky. He was close to the founder of Iran's Islamic Revolution but is at odds with the current supreme leader. Some prominent figures have rallied to his cause, including a former president, Ali Akbar Hashemi Rafsanjani.
So it is not clear how much this battle reflects a popular resistance to Ahmadinejad's hard-line policies, and how much is about a struggle for power.
It's also unclear what has propelled this calm, deliberate architect and artist — who twice refused to seek the presidency — into a confrontation with the ruling establishment of which he was once a part.
Even during the election campaign, Mousavi was less critical of Ahmadinejad than another challenger, former Parliament Speaker Mahdi Karroubi, who received only a fraction of the vote.
Associates say the real firebrand in the Mousavi family is his wife, Zahra Rahnavard, a prominent professor who campaigned by his side.
For years, Mousavi remained out of the political limelight, painting pictures — mostly with religious themes — and designing buildings, including two universities, a mosque, a museum and a shopping center.
Nevertheless, he has become the champion of a generation inspired by the hope of change, organizing protests with technologies such as mobile phones and the Internet that didn't exist when their parents overthrew the U.S.-backed shah in 1979.