As the hugely successful author of The Cat In The Hat, Green Eggs And Ham and more than 40 other children's books, Ted "Dr Seuss" Geisel was frequently approached by companies keen to use his fantastical cartoons or bizarre rhyming verses. But, despite the large wads of cash to be made, Geisel routinely refused such offers. One day, however, his attorney Herb Cheyette contacted the author with an offer that surely even he couldn't refuse. A television sponsor was prepared to pay "a vast sum of money" if they could license an unpublished verse for use on a Christmas billboard. Geisel remained adamant that he didn't want to be connected to any single product. Presuming that Geisel was just playing hardball, the company increased the offer. "This verse totals less than a hundred words," Cheyette informed his client. "If you accept this deal, you will go into The Guinness Book Of Records as the writer who received the most money per word." Geisel's reply was unequivocal. "I'd rather go into The Guinness Book Of Records," said the author, who died in 1991, "as the writer who refused the most money per word."

It is difficult not to recall Geisel's comment when considering the veritable mega-tsunami of tie-ins that have been constructed around the $100m Jim Carrey-starring adaptation of Geisel's book, How The Grinch Stole Christmas! Sure, a good deal of the revenue from such deals - plus the £8m that Universal ponied up for the rights - will go straight to the Seuss Foundation charity, now overseen by Geisel's widow Audrey. Yet if the author was horrified at the idea of an unpublished poem being used on a billboard, one can only wonder at his reaction to the fact that Americans can now buy Cat In The Hat gonks with their Grinch credit card before chowing down on a Dr Seuss-themed meal at Wendy's. But, while Geisel seems like an almost Naomi Klein-like figure of marketing restraint compared to the brand-crazy Walt Disney, he was not entirely averse to licensing out his creations. In 1983, for example, the author signed a $10m contract with Cabbage Patch Doll-manufacturers Coleco, only nixing the deal when the company proved unable to produce a Cat In The Hat doll capable of matching his perfectionist standards. Then again, Geisel was a contradictory figure. Although by the end of his life the greying, bearded author resembled every kid's idea of a lovably roguish grandfather, he never actually had any children himself and was rumoured not even to like them. "He could tolerate a couple at a time," admits his widow today.

"But that was his limit."

Geisel himself repeatedly denied having any problems with the ankle-biting community who in turn regarded him as an almost mythic figure, sending the author thousands of letters every month ("98% of them misspelt," Geisel would dryly note). It was an adoration that was deserved, as Geisel effectively saved early readers around the world from dull-arse Peter-and-Jane-go-to-the-shops-and-come-back-again primers, offering them instead an enchanting world of empty-but-walking trousers, bizarrely coloured cooked meats and North-Going Zax. Moreover, while parents could only applaud the moral to be found in a book like Green Eggs And Ham - "don't be afraid of trying new things" - the horribly determined way in which "Sam-I-am" tries to foist his comestibles on Geisel's hero indicated to children that they had found someone who was very much on their side. There is no doubt, though, that writing children's books was not Geisel's first choice of activity when casting about for something to do in his spare time while employed churning out ads for Standard Oil during the 30s. Unfortunately, the terms of his contract precluded him from doing anything else. But Geisel had no intention of putting his patronym to such juvenilia - intending to save that for his proposed great American novel - and decided instead to use his middle name. And so, with the publication of 1937's And To Think That I Saw It On Mulberry Street, Dr Seuss - Children's Author was born. (The "Dr" part was initially fictitious, but Geisel would eventually be granted a doctorate from his alma mater, Dartmouth, making him, as the author liked to point out, 'Dr Dr Seuss').

Although featuring recognisably Seuss-esque illustrations combined with his distinctive rhyming verse, Mulberry Street failed to make much impact on the public. Geisel's career as an author was soon put on indefinite hold when he was recruited to make propaganda movies during the second world war under the guidance of Frank Capra. When the war ended, Geisel continued his association with Tinseltown by writing the critically slammed 5,000 Fingers Of Dr T and working on an abortive early attempt to adapt Rebel Without A Cause. With his Hollywood career in tatters and his reputation as a children's author less than stellar, Geisel pinned most of his hopes on the still unfinished Great American Novel.

"I happened to find it six months ago," Geisel said in 1972. "It was very avant-garde and there were whole passages of Italian in it. Which I don't understand because I can't speak a word of Italian."

Geisel's life changed forever in 1954 when Life magazine published an article which found novelist John Hersey bemoaning the fact that his kids were growing up illiterate thanks to the boring nature of school primer books and concluding that the educational system should be turned over to children's authors like Dr Seuss. Publisher William Spaulding persuaded him to accept Hersey's challenge and the author set to work trying to come up with a story that used only 225 words.

"It was like trying to make a strudel without any strudels," Geisel later informed his biographers, Judith and Neil Morgan. "I was desperate, so I decided to read once more. The first two words that rhymed would be the title of my book and I'd go from there. I found Ôcat' and then I found Ôhat'. That's genius, you see!"

The result was, of course, The Cat In The Hat - the book that cemented the winning Seuss style, being bright, entertainingly absurd and yet understandable to six-year-old readers. Published to rave reviews, the book proved an instant hit which Geisel swiftly followed with the likes of One Fish Two Fish Red Fish Blue Fish and Green Eggs And Ham, the latter the result of a bet that he couldn't write a book using only 50 words.

By the early 70s, Dr Seuss had become a publishing phenomenon, a situation that finally allowed Geisel to make his mark on the adult world when satirist Art Buchwald dared him to write a political story. Geisel responded by sending him a copy of his poem Marvin K Mooney, Will You Please Go Now! which he had altered so that it concerned the then-besieged President Nixon: "You can go by foot. You can go by cow. Richard M Nixon, will you please go now!" Nine days after Buchwald published this new version Tricky Dicky did exactly that, albeit by helicopter.

But it is as the man who helped hundreds of millions of children to read that Geisel will be remembered. A figure that can only keep on rising given the fact that his anarchic creations are as twistedly intriguing to kids now as they were when he wrote them, whether gurning out of the books themselves or even - ye gods! - pictured on a credit card. As Geisel himself was wont to point out, "I finally found my level. In the kindergarten."

 The Grinch is out on Friday