Among the plethora of ‘celebrity’ biographies and autobiographies that clamour for attention in the bookshops at this time of year, there is one that stands head and shoulders above the rest.

Kenneth Williams, comedian, writer, actor, broadcaster, was no 15-minute wonder manufactured by today’s reality television.

He was an all-round entertainer who made his mark in just about every medium, starting with the armed forces entertainment service.

Christopher Stevens’ biography goes beyond the diaries, excerpts from which were published with a great fanfare a few years ago.

Stevens negotiated access to the entire collection of Williams’ detailed and revealing diaries and letters. Such are his powers of persuasion that he coaxed the actor/comedian’s closest friends and associates to talk about the complex man they knew for the first time for public consumption.

Nicholas Parsons, Stanley Baxter, Barbara Windsor, Fenella Fielding, Michael Parkinson, radio and TV producers and film directors are among those he interviewed, plus many of the less publicly known friends talked about in the diaries.

From the conversations, letters and diaries he reconstructs the life of an extraordinary man; by turn brilliant, funny, generous, sexually repressed, bitchy, mean, selfish and just plain contradictory and unpredictable.

People who counted him as a friend were horrified to learn after his death of the cruel, dismissive words he had written about them in his diary.

His stage career was chequered and often stormy with the actor frequently pressing the professional self-destruct button.

Williams fans will remember, of course, the Carry On films, his radio appearances with Tony Hancock, Kenneth Horne and later his frequent and increasingly popular appearances on television chat shows.

Stevens treats his material with loving care – he was and is an ardent Williams fan – but he makes no attempt to gloss over how impossible he could be, how he tried the patience of his dearest friends with irrational fits of pique.

It is a meticulously honest biography, not sensationalised, and charts his growing bouts of depression up to Williams’ eventual suicide.

It is eloquently written by former Bristol journalist Stevens who now works on The Observer.

Born Brilliant: The Life of Kenneth Williams By Christopher Stevens Published by John Murray