Alexei Navalny has done more than any other opposition leader to lay the groundwork for the protest movement now challenging prime minister Vladimir Putin's 12-year grip on power. His reward came last weekend when he took the stage before an estimated 70,000 to 100,000 of demonstrators.
Working the crowd like a firebrand preacher, Navalny had people responding to his calls with cries of "Yes" and "We are the Power!" His role now looks set only to grow.
He reaches tens of thousands through his blog, consistently among the top three on Live Journal, and has more than 167,000 followers on Twitter.
Navalny's description of Putin's political party as the "party of crooks and thieves" and his call to "Stop feeding the Caucasus" have become catchphrases of the opposition.
The Kremlin has woken up to the threat posed by the charismatic Navalny, but efforts to silence him have only added to his stature.
Navalny was arrested after leading a protest march in defiance of police the day after December 4 parliamentary elections. He was jailed for 15 days, but the protests only grew.
When he was released last week, Navalny said he felt that he had been "jailed in one country and freed in another." Dozens of camera crews had waited into the early hours of the morning for his release, in a sign of his growing fame.
The outpouring of public anger has shaken Putin as he prepares to return to the presidency in a March election.