Mr Happy is a fan's favourite

From there, the little round figure, with impossibly long arms and an urge to tickle anyone within reach, was born.

The irrepressible Mr Tickle paved the way for 42 more funny men, including Messrs Happy, Nosey, Greedy and Snow.

The success of the series enabled Mr Hargreaves to turn his back on the advertising world and work from home, in Kent.

Adam, now 38, said the simplicity of the characters was the key to their success.

He said: "My father was very successful in capturing basic human characteristics and turning them into something humorous.

The facts behind the Men

When the first book appeared in 1971, Mr Tickle, it cost just 15p The Little Miss books were written for Roger Hargreaves' twin daughters Amelia and Sophie There are 42 characters seen in 45 countries The original Mr Men TV series, between 1974-1985, was narrated by Arthur Lowe

"Anyone can relate to them, as people always know a Mr Happy, Mr Forgetful, Mr Fussy or Mr Messy."

The Mr Men were later followed by the Little Misses, with Miss Bossy taking the lead.

Adam continued writing books, drawing on an inherited sense of humour and creativity, after his father died unexpectedly of a stroke 13 years ago, aged 53.

His sister, Amelia Beddoe, later joined the business, helping run the Mr Men empire based in Tunbridge Wells.

The rights to the characters however, still belong to Mr Hargreaves' widow Chris.

And for those not content to own just the books, Mr Bump plasters, Mr Perfect boxer shorts and Little Miss Naughty underwear, are among the vast range of merchandise.

Mr Cheeky was created by eight-year-old Gemma Almond, from Shropshire, who won a nationwide competition.