The first thing you need to do to understand the influence of Sid Caesar on television comedy is to watch some of what’s left from the glory days. Like this parody of This Is Your Life, with Carl Reiner as the host and Caesar as the reluctant (to say the least) subject, plus Howard Morris as Uncle Goopy:

Or this exercise in foreign language-like double talk, an art at which he was an expert, with Caesar as a German general and Morris as his valet:

Or the epic parody of the then-current From Here to Eternity, From Here to Obscurity, and you can jump to part two to see the memorable beach scene:

Keep in mind that these were from the 1950s, and what came before these was… well, not much. TV sketches were largely warmed-over vaudeville, and Caesar was one of the earliest to tailor the comedy to the medium. Where Ernie Kovacs was the most technically inventive and Jackie Gleason the most popular, Caesar, who passed away today at 91, was the volatile leader of a show that’s still spoken of as influencing everything that came after it, certainly Saturday Night Live, another live sketch show which Caesar hosted in a 1983 episode at the end of which he was named an “honorary cast member.”

And then, maybe, watch My Favorite Year:

Caesar was not Alan Swann, but the movie was roughly based on the writers’ room at Your Show of Shows and Errol Flynn’s guest spot on the show. Oh, that writer’s room. Between Your Show of Shows, the subsequent Caesar’s Hour, and specials that Caesar did in the ’50s, Caesar’s writers included Neil Simon and his brother Danny, Mel Brooks, Woody Allen, Larry Gelbart, Mel Tolkin, Carl Reiner, Lucille Kallen, Aaron Ruben, and Selma Diamond. And Reiner went on to create The Dick Van Dyke Show, which… well, let’s just say that the vain, slightly unhinged Alan Brady (played by Reiner) bore a striking resemblance to Caesar.

And definitely go check the Twitter timeline of showbiz historian Kliph Nesteroff today — you really should follow him if you’re at all interested in the great lost showbiz performers of the bygone era, and you should be — for an avalanche of quotes about Caesar and links to more video. Speaking of quotes, go get one of my favorite books of all time, Jeff Kisselof’s oral history of the early days of television The Box, and read the section (starts on page 308) about the writers’ room, in which Howard Morris (later a top TV director and cartoon voice guy, and Ernest T. Bass on The Andy Griffith Show) tells of being hired because he was small enough for Caesar to pick up by the lapels, and Mel Brooks stages not one but TWO holdups. It was an insane bunch doing insane things in the name of comedy.

Why, then, is Sid Caesar, a household word in the 1950s, so obscure to people under 50 (or even older)? For one thing, most of his best material was lost — predating cheap videotape, NBC discarded the kinescopes and what’s left was what producer Max Liebman and Caesar kept themselves. For another, he spent several years in the throes of addiction to pills and alcohol which took him out of commission in what should have been his prime. But he did show up on occasion: You’ll see him in It’s a Mad, Mad, Mad, Mad World, Grease and Grease 2, Mel Brooks’ Silent Movie and History of the World, Part I, Vegas Vacation, and a few other things. Not his best, but at least they were acknowledgements of what he meant at a pivotal moment, as TVs invaded living rooms and comedy invaded TV.

He was difficult, tempestuous, creative, a little — maybe a lot — crazy, and highly influential. That’s why he matters.

Just heard about Sid Caesar. I don’t think there’s ever been a funnier human being.

— Albert Brooks (@AlbertBrooks) February 12, 2014

Sid Caesar is forever.

— Greg Proops (@GregProops) February 12, 2014

Life…doing her thing, another great has passed Sid Caesar. Funny man We honored him at the very first Comic Relief. RIP turn turn turn

— Whoopi Goldberg (@WhoopiGoldberg) February 12, 2014