It is early afternoon in a hot and steamy Beverly Hills. Sid Caesar's sprawling hilltop house perches on top of a lush canyon that overlooks the bustle of the city. Up here the air is clear and tranquil, punctuated with the sweet-smelling fragrance of jasmine and gardenia. It has been the Caesars' home for more than 40 years.

Sid Caesar has been described as the greatest ever American comic. Known as one of television comedy's most intelligent and provocative innovators, he is famed for having pioneered a new brand of humour. During the '50s, he became a fixture on Saturday night television with his 90-minute live variety programme, Your Show of Shows, a mix of ground-breaking parodies and sketches.

The show also launched the careers of some of the industry's most gifted writers, including Mel Brooks, brothers Danny and Neil Simon, and a young Woody Allen. They wrote and Caesar performed, playing his favourite characters - the henpecked husband, the greasy-haired cad, and the multi-linguistic double-talking foreigner. Critics dubbed him the Charlie Chaplin of television - one notoriously harsh critic even claiming him to be "one of the wonders of the modern electronic age".

Scenes of Caesar's foreign-tongued nonsense patter are now among the most popular videos on YouTube. Together, they have racked up millions of hits.

All of which leaves the 89-year-old chuckling in amused bewilderment. "I never knew… I have a list of people who have written me letters about this and it's woken me up because it's all over the planet. I never knew how people around the world felt about me. The internet has made me realise."

Snapshot

BORN: September 1922 in New York. Russian-Jewish immigrant parents ran a diner
CAREER: Trained as a saxophonist. Turned to comedy, performing at hotels in the Catskill Mountains. Became famous as the host of Your Show of Shows, a ground-breaking variety programme scripted by Woody Allen and Neil Simon
PERSONAL LIFE: Married for 67 years to Florence, who died this year. Three children

He shakes his head in awe. "It's amazing. Just amazing. It makes me feel very small."

Caesar has spent almost 70 years entertaining audiences in every medium - from radio and television to films like It's A Mad, Mad, Mad, Mad World, Silent Movie, and Grease. He left school at 16, immersing himself in music long before he discovered comedy as a career. Over the years, assisted by a Juilliard education, he became an accomplished saxophonist - he also played the clarinet and flute - and by 18 was playing in orchestras alongside Shep Fields and Benny Goodman.

But it was not steady work, so he would slip away into the Catskills every now and then to appear in Jewish hotels and clubs in the so-called "Borscht Belt", performing sketches and honing his skills. Televison producer Max Leibman caught his act, liked what he saw and put him in his shows. He saw the way the young man worked his audience, how funny he was with his multi-lingual patter that sounded as if he was fluent in a dozen languages. Audiences did not realise he was spouting words that made no sense. He captured the nuances of the language and the comedic facial expressions of the speaker. French, Italian, Yiddish, German, Russian. They became synonymous with his name.

"I didn't know I could do it," he reflects now, "but I tried and people liked it. So I continued doing it."

He grew up in Yonkers, a predominantly Jewish suburb of New York. Yet as a performer he deliberately avoided the kind of Jewish neuroticism that Woody Allen exhibited in his stand-up days. "I made a conscious decision to stay away from that. There's a lot of fun that you can bring out in being Jewish. But I didn't want to make fun of being Jewish. There's a fine line."

He launches into a monologue of Hebrew that is made up of a stream of words but is total gibberish ("elohaynu shalom abba yomtov adonoi omayn!") That is a safer kind of fun, he says. "I used to see people davening in shul and they'd snap the book shut when they'd finished. Like they'd won a race. Then look around to see if anyone else had finished. I used to find that very funny."

His religious learning began early. "I went to cheder when I was five and did eight years there leading up to my barmitzvah. I don't know that I was a good student. I did all the usual things that Jewish kids do."

His barmitzvah was "a very big deal" and even then, he recalls, he was master of his own words. "The rabbi wrote me a speech and I told him: 'No, I'll write my own. I'll say what I want to say, how being Jewish has affected me and what it means to me to be a Jew.' You have to be honest and speak from your heart."

For Caesar, one of the special things about Jews is a talent for comedy. "Jews have a good sense of humour. Jews appreciate humour because in their life it's not too funny. We've been trodden down for a long time, thousands of years. So we've had to turn that around because if you take it all too seriously you're going to eat yourself. And we're very good at being self-deprecating. Either we do it or somebody's going to do it for us. We might as well do it first."

In his heyday, Caesar was surrounded by a gang of writers, all of whom were Jewish. But that, he says, was sheer coincidence. "I didn't hire them because they were Jewish. I hired them because they were the best. When you have Mel Brooks, Neil Simon, Carl Reiner and Woody Allen… they were genius. To have them work with you - that was a mitzvah."

Caesar was a real fan of Allen, who was the only one of his team who also performed as a stand-up comic. "I used to watch Woody when I went down to Greenwich Village. He was just tremendous. Every subject he did he really wrung it out, he did everything about it and upside down and inside out. And when he was through with a subject there was nothing much more you could do with it."

He remembers the first day the comedian came to work for him as one of his writing team. "When Woody walked in we were all sitting in the writers' room and… who brought Woody in? Larry Gelbart, who wrote M.A.S.H. Larry was an immense writer, he really was funny and he could deliver. And Woody knew he could capture my sense of humour. He'd seen me work so he knew what he was going to do, he knew how to write for me."

Reflecting on the creative process, Caesar recalls the panic that the team suffered at the start of every week. "When we came in we didn't have the slightest idea of what we were going to do. We christened the beginning of the week 'Bloody Monday' because we walked into the room with no material. We had three days to pitch lines and ideas and create six complete sketches.

"The writers sat around in a horseshoe and would pitch ideas, jokes and dialogue. I sat in front of them as they pitched. Larry Gelbart bought me a golden upholstered chair to serve as a throne for the writers' room so I could preside in style.

"These guys had tremendous energy and creativity and would fight for lines. When it came right down to it we operated under a variation of the Three Musketeers ethic: all against each other but all for the show. What was best for the show was the main thing. As much as they all fought with each other they respected each other."

Inspite of being incarcerated with each other five days a week dealing with the stress of having to come up with a live, scripted programme at the end of each week, the Caesar gang was a tight-knit family. "I think the most important aspect of this working environment was that when we went out to lunch we all sat at the same table and we all laughed together. I respected all of my writers and worked hard to maintain their respect."

Almost 50 years later, Caesar's pride in his shows is palpable. "What we did," he reflects, "is now considered classic comedy. We created formats, concepts that transcended vaudeville and helped establish television as the pre-eminent source of entertainment in the world."

Caesar' s own comedy roots were planted early. Humour was a vital ingredient in his family structure. His parents ran a 24-hour restaurant and the little kid from Yonkers saw a kaleidoscope of life at a young age.

"We saw the guys come in from down the street… there was a bar a few doors down and they used to get drunk and come in. They'd pour a whole bottle of ketchup into the soup. You had to have a sense of humour to deal with that.

"My brother, Dave, was very funny. He was 10 years older than me and he took me down to New York when I was just a kid and I saw these great stars like Danny Kaye. I watched them all and fell in love with them.

"And there was Buster Keaton. He was incredible. I met him when he was in a picture I made - It's a Mad, Mad, Mad, Mad World. He had one scene in a garage backing a car out and he turned it into a ballet. Right in front of me. It was fabulous."

His greatest influence, however, came from his parents' restaurant where he developed his talent as a dialectician by mimicking the voices of the European, Russian and Polish customers.

"I have an ear," he explains. "Every language has a different tune. It's all a song. It's all about where you put the accent or what you talk about."

But for all his success, Caesar suffered tremendous insecurities which ultimately damaged his career.

"On stage I could hide behind the characters and inanimate objects I created. Off stage, with my real personality for all to see, I was a mess… I couldn't believe that anyone could like me for myself."

Away from the camera, he drank excessively until he found himself combining tranquilisers with alcohol. "I couldn't stand me," he says. "That's why I drank and took pills. I couldn't stand to be around me."

Like many comics, he thrived on the audience response but he was unable to appreciate the success which had happened so fast. He had shot from nowhere to stardom in the space of a few years. Deep down, he feared he did not deserve it and it would all disappear.

During the peak of his fame, he earned a reputation as being more than slightly meshugeh and agrees today that some of his actions were extreme. On a hot day in the writers room, he would strip down to his underpants. "People would come into the room and say: 'Where are your trousers?' I'd say: 'It's a hot day, I don't want to get them creased.'"

Eventually his work became affected. "I'd just drink more," he recalls. "I was sick, burned out. I'd had too much booze and too many pills."

By the late '70s, Caesar had fallen prisoner to the alcoholic-drug syndrome, trapped in his bedroom for months. When he appeared in a play in Canada, on the opening night he forgot his lines and never made it to the second act.

His recovery began in Paris while making the film, The Fiendish Plot of Dr. Fu Manchu, with Peter Sellers. Talking to himself daily into a tape recorder allowed him to pit, as he puts it, "Sidney the counselling father against Sid the wayward child who wanted to drink and take pills." It was a long struggle but finally the father won the battle.

These days, Caesar is having to cope with another trauma - grief at the death of Florence, his wife of 67 years, earlier this year. "We were together so long," he says softly. "I got married very young. I was 20. She was very special. And she made me. She was much smarter than me. She told me how to act and my success is all because of her."

Providing a little solace is his keen interest in British comedy. Among his favourites are Marty Feldman and Peter Sellers, whose vocal repertoire was rivalled only by Caesar's own. And there is one particular group of performers which leaves him in stitches every time. "Monty Python," he says gleefully. "They did some wonderful stuff together. I found them on a BBC broadcast and I watched in absolute awe. It was funny, I mean really funny. The wonderful ideas and the way they carried them out. Crazy! You didn't have to understand English humour to understand them. Funny is funny whether it's British or African or whatever."

The conversation turns again to Judaism. He used to go to synagogue but not that often, he admits. "We didn't really live a very Jewish lifestyle but I did like to daven. I believe in prayer and I'm proud to be Jewish."

Will he consider a second barmitzvah when he turns 92, like Kirk Douglas a few years ago? He laughs wryly: "I had one and one was enough. For me, it's enough to be a man once in my life."