The word “legend” refers to a great many people who have worked in Hollywood. But when you’re talking about a movie star or a fabled director, the essence of the legend can be found up onscreen. With a producer, the legend usually has more to do with the shadow world offscreen — with what, exactly, he did to get a movie made. And as surely as the studio-system era was built on such legends as the pitch-perfect vulgarity of Samuel Goldwyn or the control-freak tyranny of Louis B. Mayer, the Hollywood that came after them had the high-wire, livin’-large effrontery of Robert Evans.

A former cheeseball actor who took over as the head of production for Paramount Pictures in the late ’60s, guided it back from the dead, and presided over as brilliant and game-changing a run (“Rosemary’s Baby,” “The Godfather,” “Chinatown”) as the movies had ever seen, Evans represented a unique fusion: of the Old Hollywood and the New, of the desire to make hits and the desire to make art, of the producer as backroom wheeler-dealer and the producer as sexy media-age showman. Evans could be all those things at once because even at the height of his power, he never stopped regarding himself as an actor, as a player who succeeded by taking on the role of a player.

Anyone who has seen “The Kid Stays in the Picture,” the scintillating 2002 documentary that Brett Morgan and Nanette Burstein made out of Evans’ 1994 autobiography (which become a cult hit mostly because of the books-on-tape version, which Evans read in his Robert Mitchum-meets-Henny Youngman jabber), knows that Evans’ career was a hall of mirrors. Born in 1930, he was working as the vice president of the Evan Picone clothing company (which, according to him, launched the concept of women’s slacks) when he was discovered at the Beverly Hills Hotel swimming pool, in 1957, by Norma Shearer, who helped cast him, out of the blue, as her late husband, the MGM producer Irving Thalberg, in the James Cagney-as-Lon Chaney biopic “The Man of a Thousand Faces.” It was a stroke of fate that presaged Evans’ own career as a studio executive.

You can see why they thought he’d be a movie star in the late ’50s. Evans was gleamingly handsome, yet he always had a touch of the geek about him. With his toothy grin and beautiful slick coif, he looked a cross between Tom Cruise and the young Donald Trump, and as his career as an actor fizzled, the role of producer became the perfect fit for him. He was born not to tell a story but to sell it. Even his ascension to the upper ranks of Paramount was the result of a media parlor trick, when Peter Bart, the West Coast correspondent of The New York Times (and, later, the editor-in-chief of Variety), wrote a profile of him in 1966 that highlighted Evans’ new-style aggressive skill at seeking out and cultivating adaptable manuscripts before they were published (or even finished). This, it turned out, would prove to be a pivotal producer’s strategy in the new era, and Evans excelled at it. He also parlayed the buzz over that Times piece into the top job at Paramount, forging an uneasy alliance with Charles Bludhorn, the head of Gulf & Western, that would come to define the tensions of Hollywood in the age of conglomerate control.

You can see the yin-and-yang of Evans’ achievement in the two films he shepherded that relaunched Paramount and set the cinematic tone for the entire 1970s. “The Godfather” was the most important film of the decade, and it wouldn’t have been made the way it was without Robert Evans. In hiring Francis Ford Coppola, Evans grasped that the then-moribund gangster genre needed a major helping of ethnic authenticity; as much as that, he saw that it needed to be epic. The result was a new benchmark in operatic Hollywood realism. At the same time, Evans understood the populist lure of “Love Story,” a romance with four-hanky storytelling values that couldn’t have been more antithetical to those of the New Hollywood. In some essential way, Evans anticipated the conservative “Rocky” aesthetic that would, by the end of the ’70s, replace the new era.

He was, throughout, the last larger-than-life image of the producer-mogul, ensconced in his Beverly Hills chateau, married ( for a moment) to Ali MacGraw, palling around with Jack and Roman, a former glamour boy who still envisioned himself, on some level, as a movie star. In “The Kid Stays in the Picture,” Evans presents himself as a contempo film-noir tough guy (Evans to Ali MacGraw: “Never plan, kid. Planning’s for the poor”).

But the thing about Robert Evans is that he walked the walk. When he left the studio aristocracy and ventured out on his own, making features on contract to Paramount, he could easily have landed in the weeds, but instead he took Robert Towne’s script for “Chinatown,” which was originally so dense that no one could understand it, and used his producer’s alchemy to mold it into a great movie.

For a while, he could do no wrong, and his media presence, which he cultivated with Trumpian cunning, escalated right along with that of his friend Jack Nicholson. Yet the culture was changing, and Evans, as one of the kings of it, was having too much fun to notice. In 1980, he was tagged in a drug bust (he couldn’t resist the lure of buying pharmaceutical cocaine), and the descent that followed was as decisive as the rise. That he lost his touch as a producer had as much to do with the era as it did with him. The saga of “The Cotton Club” is all about how Evans, and Francis Ford Coppola, thought that they were making a new “Godfather” — but, of course, this was the high-concept tinfoil version. And that wasn’t Evans’ fault. Nor was it his fault that he was a bit player in what became known as the “Cotton Club” murder. Yet that tabloid crime tainted him as if he’d been an accessory.

Was his downfall out of Greek drama — as in fate, karma, his own nature catching up with itself? Was he Charles Foster Kane as profiled by “E! True Hollywood Story”? Holed up in his rosebud-filled chateau (which Nicholson had to plead with the owner to sell back to Evans), with no one interested in working with him, he was, for a while, just that. And when Dustin Hoffman, in 1997, based his performance as a Hollywood producer in “Wag the Dog” on Evans (in “The Kid Stays in the Picture,” the closing-credits outtake of Hoffman’s riff is a scalding classic), it seemed as if it was Evans’ manic-nerd demeanor that was becoming legendary.

He had a comeback, of sorts (if you can count movies like “Sliver” as a comeback). Yet the ultimate truth of Robert Evans’ career is that it was his instincts as a producer that were legendary. He believed in the movies he was making. And it was his destiny to arrive at a moment when the revolutionary artists who were coming up in Hollywood needed someone to believe in them. Robert Evans was that someone. In producing the films he did, he changed film history, making himself a timeless character within it.