His interviewees didn’t realise they were being hoaxed and, faced with an earnest, not very bright young man, they’d do their best to treat his questions respectfully. An eminent zoologist would be asked if the theory of evolution meant that his nan had had sex with a monkey; an economist would have to ponder whether supply and demand meant that “I supply it and me Julie demand it”. Cohen’s ability to deliver these questions with a straight face made for deliriously embarrassing viewing.In March 2000, after three series, he moved on to Da Ali G Show, a Channel 4 vehicle that averaged 2.4 million viewers. But the character was already being attacked as a malign stereotype. The media whipped up a debate about whether Ali G was meant to be a black character or, as his defenders argued, a white wannabe. Surreally, some pundits argued that Ali G was a British-Asian who wanted to be black. Felix Dexter, the black comedian, compared him to Al Jolson, saying Cohen “allows the liberal middle-classes to laugh at black street culture in a context where they can retain their sense of political correctness”.

On BBC2′s Late Review, Tom Paulin frothed that he belonged to the same evil tradition of denigrating caricatures as Britain’s Irish jokes Cohen himself refused to be drawn. Making a mockery of those who discuss their divorces in OK! magazine because, they claim, the publicity is vital to their careers, one of the most phenomenally successful performers of his generation got where he is today without ever opening up to journalists about his private life or opinions.But he’s not mysterious or reclusive, and a fair amount of background details are on record He grew up in north-west London. He attended Haberdashers’ Aske’s public school with his two brothers. He studied history at Cambridge, where he is remembered more for his suitably over-the-top roles in university productions of Fiddler on the Roof and Tamburlaine the Great than for his appearances in Footlights revues. However, one Footlights contemporary, Dan Mazer, is now his producer and co-writer; another, novelist Will Sutcliffe, contributed to Da Ali G Show. He and his older brother ran a comedy club, and Cohen did all the things that comedians do while they wait for the big break.

Magazines have reprinted pictures of his catalogue-modelling; the TV series Before They Were Famous has unearthed footage of him conducting phone-ins on TV shows.Having clocked up some time doing links on the Paramount Comedy cable channel, he put himself forward as a hoax interviewer for The 11 O’Clock Show. In his audition video he played Borat, a reporter from Kazakhstan with an Ali G-ish line in disarming innocence. Producer Harry Thompson steered him towards a more youth-oriented character, and in 1998 Ali G was born.Right from those first 11 O’Clock Show segments, he was as much an object of satire as the people he interviewed – a man unaware that there was anything risible about “bigging up” the West Staines Massive or the Langley Village Posse. In his own series, his foolishness was emphasised further: he was shown frowning over a Jamaican phrasebook, trying to decipher the patois of the black DJ. And you might argue that it wouldn’t matter what colour the character was intended to be.