HE'S not so much an entertainer, more of an institution. In a career spanning almost the whole of the last century, Bob Hope carved out an unparalleled niche as a vaudevillian, film star, comedian, presenter and all round showbiz legend.

The wisecracking star of The Road To... movies; hero to GIs from the Second World War to Desert Storm; Oscar host, including the first televised ceremony; star of his own TV show for more than 40 years - his has been a career which is unlikely ever to be matched, either in its longevity or its accomplishments.

He is the richest comedian of all time, amassing at least £400m, and when he dies, his seven million jokes will be interred in the £2.5m Bob Hope Gallery of American Entertainment in Washington's Library of Congress. He has been knighted by the Queen and given the Congressional Medal by President Kennedy.

Off-stage, he has cultivated the image of a dedicated family man, married to the same woman for almost 70 years; a friend and golfing partner to presidents from Truman to Clinton; a self-deprecating charmer. He was considered an unofficial ambassador for the US, so popular that the US navy named a ship after him - the personification of American values.

But, with the deterioration in his health as he approaches his 100th birthday on Thursday, so the reality behind the image has emerged. The stories of his serial infidelity, leaving behind him a string of heartbroken mistresses, some of whom subsequently committed suicide; stories of his harsh treatment towards his army of more than 100 writers, and stories of his brutality towards those who displeased him.

But, whatever the personal failings, it is impossible to discount the achievements of a man who rose from abject poverty to become the most successful entertainer in history.

Leslie Townes Hope was born the fifth of seven sons in Kent on May 29, 1903. When he was four, the family emigrated to America to start a new life, settling in Cleveland, Ohio, but his stonemason father Harry struggled to make a living and the young Leslie left school at nine to embark on a series of odd jobs.

After a brief spell in jail for stealing tennis balls, and an unsuccessful stint in the boxing ring, at 18 he turned to the stage as a singer and dancer, changing his name to Bob, thinking it would look better on the posters.

Within a few years, he had become a Broadway star in the musicals Ballyhoo and Roberta, but his sudden fame coincided with the breakdown of his marriage to Grace Troxell, another performer. A year later, he met Dolores Reade, a nightclub singer, but although the couple have been together for almost 70 years, and have four adopted children, no one has ever been able to produce a certificate for his second marriage.

Hope had appeared with emerging star Bing Crosby in Ballyhoo, and the pair struck up an insult-hurling rapport, which came to the attention of Paramount Studios chief William LeBaron. Paramount had been looking for a cast for The Road to Mandalay, about two vagabonds on the run in the South Pacific, and LeBaron decided to try Hope and Crosby. The title was changed to The Road to Singapore, Dorothy Lamour was added for glamour, and it turned Hope into America's favourite comedian.

The film also spawned a franchise, with Zanzibar, Rio, Morocco, Utopia, Bali and Hong Kong following hard on Singapore's heels, with Hope's film career also including The Cat and the Canary, My Favorite Blonde, Here Come the Girls, That Certain Feeling and The Facts of Life. His radio show, with the signature tune, Thanks for the Memory, became enshrined in American popular culture, and his tv series, The Bob Hope Show, ran from 1950 to 1993.

Along with other stars, Hope volunteered to entertain the troops during the Second World War, but none matched his instant rapport with the audience. And few were willing to give so much of their time, and put themselves at risk so frequently. From Korea and Vietnam to Iraq and Desert Storm, Hope braved the dangers to give the boys a laugh.

But behind the facade of the great entertainer lay a turbulent - and, at times, unsavoury - personal life, kept hidden from the public by a combination of his immense wealth and influence.

For the truth was that Dolores Reade had to put up with a series of infidelities, as Hope seduced a procession of impressionable starlets and others beside.

Tales of his womanising are legion - on one occasion he persuaded his doctor to book him in to a hospital solely so he could engineer an encounter with a pretty nurse, recommended to him by Crosby, who had previously enjoyed her ministrations.

But while Dolores turned a blind eye to his roving, Hope left heartache and destruction in his wake. Starlet Barbara Payton turned to alcohol and eventually killed herself after Hope ended their affair; Rosemarie Frankland, the first Briton to be crowned Miss World, had a 20-year relationship with Hope but at the age of 57 died from an overdose, and Hope's former personal assistant Ursula Halloran also took an overdose when their relationship cooled. Hope went to Halloran's funeral, but was run out of town by Ursula's sister, a nun.

Hope's appearances at funerals of ex-lovers, often delivering eulogies from the pulpit, humiliated Dolores, as did the installation of mistresses in apartments close to his estate in North Hollywood, handily placed so he could break up his midnight stroll with a sexual encounter.

But Dolores was not the only one left humiliated by Hope's behaviour. When it came to paying the 100 writers who came up with his jokes, and had to be on call 24 hours a day, he would fold their cheques into paper aeroplanes and fly them from the top of the stairs, watching as the hapless hacks lined up to catch their wages.

The last few years have seen a serious deterioration in Hope's health. Deaf, almost blind and with a weak heart, nowadays he is said to rarely leave his bedroom. But he takes comfort from the fact he has outlived all his contemporaries and rivals, driven by the desire to reach 100 and match George Burns, a milestone he should pass on Thursday. Whatever his personal failings, as an entertainer he was unsurpassed and we will not see his like again.