Robert De Niro, Tribeca Film Festival Founder

That first year, the festival was a hit critically and commercially, drawing 150,000 attendees and generating $10 million in revenues for local merchants, with stars including Susan Sarandon and Hugh Grant adding a frisson of glamour to the serious New York film crowd. Most gratifying for De Niro, Rosenthal, and Hatkoff, downtown residents embraced it as a celebration of renewal, turning out in droves for free events such as a family street fair, a concert, and open-air "drive-in" screenings of Grease on a pier overlooking the Hudson.

"The Tribeca Film Festival is an event that brought hope to Lower Manhattan in its darkest days," says New York City's mayor, Michael Bloomberg. It has grown every year since and developed a hip global identity that is more fun and fabulous than the New York Film Festival, with more grit and gravitas than Cannes. In 2006, 465,000 people came to see over 800 screenings of films from 40 countries, and Tom Cruise roared in on a motorcycle to unveil Mission: Impossible III.

One of the most respected screen actors in history, indelibly identified with New York through the street characters he has played in such films as Mean Streets and Taxi Driver, De Niro has fueled the success of the Tribeca festival, just as Robert Redford has defined Sundance. A meticulous Method actor who disappears into his characters, he is famously shy, a reluctant interview subject, and guarded about his private life. "I've never been one of those actors who has touted myself as a fascinating human being," De Niro has said. "I had to decide early on whether I was to be an actor or a personality." He relies on Rosenthal to guide him to festival functions, where he is a gracious if reserved presence. "Just tell me what you need me to do," he tells her.

Meanwhile, at 63, De Niro continues to take on new challenges. His latest film, The Good Shepherd, is the actor's first directorial effort since A Bronx Tale 13 years ago. An epic spy drama starring Matt Damon and Angelina Jolie—with an extended cameo by De Niro—the movie tells the story of the early days of the CIA by tracking a young spy, played by Damon, from his college days pre-World War II through the cold war and ending at the Bay of Pigs invasion. The tale's fictional locations range from Washington, D.C., to the Congo, Cuba, and Central America. "Being a kid raised during the cold war, it was always fascinating to me," says De Niro. As an elementary-school student, he was told to get under his desk in case of a nuclear attack. "Kind of ridiculous," he says. "I was fascinated by what the Soviet Union represented—the ominous, dangerous other side—the way we were supposed to perceive it. The propaganda."

Indeed, De Niro has been doing research on the world of espionage for the past decade (not including his hilarious turn as the ex-spy who gives his daughter's boyfriend a polygraph test "just for fun" in Meet the Parents). He has soaked up spy culture on trips to Russia and elsewhere with his friend Milt Bearden, a retired 30-year CIA veteran. "We have wandered into the hills of Afghanistan, disappeared with my old KGB enemies, who are now my friends, in Moscow," says Bearden. "Bob and I drank vodka and took saunas with these old guys, took a ride on a boat on the Moscow River." Although recognized around the world, De Niro stays as low-key as possible. "There's always a wonderful bit of mystery about De Niro," says Bearden. "It's part of what makes him a special guy. He wants it that way, and he's managed it remarkably well."

On the set of The Good Shepherd, De Niro was collaborative, doggedly perfectionistic—and modest about his relative inexperience. "There is never, as far as I'm concerned, much of an easy day," he says. "It's always not knowing, following instinct, being flexible. Because no matter how well you plan something, it never turns out that way when you are shooting. You always have to figure out on the spot what is the best thing to do with what you have." When he gets in a jam, does he ever think, "What would Marty [Scorsese] do?" "Yes, I've thought, 'What would Marty do?' " he says, laughing. "Sometimes I know exactly what he would do, and sometimes I'm not sure."

With the December 22 opening of The Good Shepherd approaching, De Niro admitted to anguishing over every last detail. "I'm fine-tuning this, reworking that," he says. "I keep having this image of the director being dragged from the editing room in a straitjacket."

As he gazes out his office window at the bustling activity around the World Trade Center site, he can take solace in one certainty: the film festival he and his partners founded has had a profound healing effect on Tribeca, pumping $325 million into the local economy. "It has been well received," says De Niro, with typical understatement. "People come from different parts of the world and want to be part of it. It has certainly contributed to revitalizing the neighborhood. Yes, I would hope that it has helped."

* The name of this award was originally the Impact Award. In 2008, the awards were renamed as the Inspire Awards.