Twenty-five years ago, standing in the Grand Ballroom of the Pierre hotel to watch Sid Caesar receive the Alan King Award in American Jewish Humor, I knew a lot more about Alan King than about Sid Caesar.

So did anyone else under 50 there that night. King, after all, was all over television then, while Caesar, who’d been a fixture on TV during its formative years, was invisible. That night, singing Caesar’s praises as the master of ceremonies, King’s first challenge—at least with folks like me—was to be believed.

After calling Caesar “probably the greatest comic talent we’ve ever had,” he ticked off the names of other Jewish artistic luminaries. “In this pantheon, this bearded old Jew is right up there with the gods,” he added, pointing to the aged man sitting nearby. “Really.” And his “really” really said it all, for it was hard to imagine that this shrunken man, so reduced from the buff shtarker he’d formerly been, had ever been funny.

Three of his younger disciples were on the program that night. Two, Carl Reiner and Larry Gelbart, were there via video. Reiner, who’d served a decade-long apprenticeship under Caesar on Your Show of Shows and Caesar’s Hour, called him “the most brilliant comedian that lived on television in the history of time.” Mel Brooks, by contrast, had actually shown up, and not just because The Producers was in rehearsals a few blocks away.

“No Sid Caesar, no Mel Brooks,” Brooks liked to say, and that was incontrovertible: Caesar had discovered, protected, endured, and nourished him. Brooks too came to praise Caesar. But more impressive than anything he said of Caesar was how tenderly he treated him, shepherding him onto the stage, embracing him once there, kissing him after placing a medal around his neck.

Several years passed before I set out to write a book about Sid Caesar. And when I did, like Alan King before me, I first had to make a case for him. It was a problem Brooks alluded to when we’d talked. “You really know, you really understood, the show,” he told me. “Now you’re going to do this book, and people are going to say, ‘Gee, this is really good and really interesting. Just one question, David: Who’s Sid Caesar?’ You’re going to get that. ‘Who was Sid Caesar?’”

I spoke twice to Caesar himself, who’d grown more wraith-like and fragile since the banquet, confined to a hospital bed in his home in Beverly Hills. Despite his physical decline, he’d actually grown more lucid over the years, with alcohol and tranquilizers no longer clouding his mind.

Several of the mainstays in his story—including his co-stars (Imogene Coca and Howard Morris) and a number of alumni of his famous writers’ room (Gelbart, Neil Simon, Mel Tolkin, Lucille Kallen)—were either gone or unavailable. But Brooks, Reiner, and Woody Allen were still around, and generous, for a variety of reasons. They were grateful to Caesar, and knew they owed him a lot. They wanted to help restore him to the place he deserved. And they hoped that, maybe, at long last, talking about Caesar might help them to figure him out.

It was easy finding Caesar’s disciples. There was Carol Burnett, who, newly arrived in New York, passed up a chance to see My Fair Lady to watch Caesar rehearse. And Conan O’Brien, who decided as a 10-year-old to become a comic after watching Caesar spoof the TV show This Is Your Life—a classic sketch containing what remains television’s longest laugh ever. And Billy Crystal, for whom Caesar “was just somebody you couldn’t take your eyes off of, even as a five- or six-year-old.”

And Richard Lewis, who recalled how watching Caesar encapsulate so much of the human condition in his sketches, soliloquies, and pantomimes eased his own troubled adolescence. And Phil Rosenthal, Judd Apatow, Larry Wilmore, and several other self-styled “comedy nerds,” who threw a small dinner for Caesar once in Los Angeles, where Caesar came back to life as they re-enacted several of his most famous routines.

Allen told me of the night at Michael’s Pub in 1990 when he and Dick Cavett watched Caesar and Coca reprise a few of their comedic duets. He and Caesar had been out of touch for decades, he said, but Reiner had told him how much Caesar had enjoyed his films. “He probably did see himself all over stuff I’ve done,” Allen told me.

Caesar was “superb” that night, Allen recalled. And afterward, he and Cavett had gone backstage to congratulate him. “Funny, that I’m going to be a footnote in your life story,” Caesar told him. “And I thought, ‘What a way to think of it, and completely untrue!’” said Allen. “‘You’re Sid Caesar, and you’re not appreciating what a genius you were and what an influence you are on everybody. You’re one of the greatest comedians that we’ve ever had.’

“He’d felt that he had come upon harder times and that he had been forgotten to a large degree,” Allen went on. “That wasn’t so with those of us who knew him. To me, he was always majestic.”

David Margolick is a New York–based reporter, editor, and author of several books