The King of Cool is certainly not a new concept in Hollywood. We've seen it used in reference to Marlon Brando (Streetcar Named Desire—era), Clint Eastwood (still kickin' it so many decades later), and, of course, the late James Dean. But you'd be hard-pressed to find someone who has held onto that mantle longer than Steve McQueen. And this despite the fact he's been gone for nearly 40 years and that his first leading man role was in a movie called The Blob (he went on to bigger and better, though the film does have its following). The natural question to ask is why? What was it about Steve McQueen that has stood him apart from virtually everyone?

Journalist/author Marshall Terrill is the guy who probably knows McQueen better than anyone without actually knowing him. He has either written or co-written half-a-dozen biographical books on the subject, with another half dozen on the way. "There is such a need for McQueen," he exclusively tells Closer. "It's kind of like Elvis — it's unending."

But, again, we ask: Why?

"The most fascinating thing to me is that when I did that first book in '93, I thought that he would have had his run, like Humphrey Bogart did in the '70s, when film fanatics had his posters on their walls," he says. "They started doing that with McQueen in the '90s and I thought that that would have been his one time around. A final victory lap. But it just keeps going and growing, and it baffles me. It's the only aspect of this whole thing that really baffles me, the way it continues to perpetuate itself. Now it's become a generational thing in that it keeps moving up, and all the young kids discover who he is and are, like, 'Wow, this guy was really cool. He was something else.'"

Below, a look back at Hollywood's forever beloved King of Cool.