She was the central and seductive figure in a searing story of sex, intrigue and espionage which led to the shaming of John Profumo, who was forced to quit his job as War Secretary, and to leave Parliament altogether.
It was a scandal which was both seedy and sinister, uncovering a hitherto secret world of sex, horse-play, drinking orgies and spying, in high places, in which Ms Keeler shared her favours with Mr Profumo, and Commander Eugene Ivanov, a Russian intelligence officer and the Soviet assistant naval attache in London.
The security implications - and indeed the security consequences - of a British call girl sleeping both with the War Secretary and a palpable Soviet spy were breathtaking.
Astonishingly, the patrician Prime Minister, Harold Macmillan, could not believe at first not only that such things could happen, but worse, that the trusted, brilliant and ambitious John Profumo could have been embroiled in them.
It was only after Mr Profumo was forced to admit that he had lied to the Commons in March 1963 when he denied any impropriety with Ms Keeler, that Mr Macmillan accepted the full enormity of the scandal.
The Conservatives, already looking careworn, had been in office for nearly 13 years, and this explosion of sleaze and scandal at the top echelons of society was more than enough to help topple them from power.
Christine Margaret Keeler was born in 1942. She left school at the age of 15 and left home, at Wraysbury, Bucks, a few months later. She worked as an office junior, a showroom assistant and a barmaid.
Before she was 16 she was working as a showgirl in a club in Greek Street, in the heart of London's red-light Soho district. She was said to be earning about £8 a week.
After 1960, there was no obvious employment in her records, almost certainly because she had become what in those days was euphemistically termed a model.
It was during this period that she found herself launched into the unsavoury world of high-society osteopath Dr Stephen Ward, variously described as an artist and a procurer of women, as well as suspected of being a double-agent.
This marked the beginning of the biggest political sex scandal of the 20th century.
Christine Keeler was stunning, leggy and red-headed and was soon moving in Mayfair's smartest but not necessarily the most savoury circles. Dr Ward, who lived in a Thames-side summer house on Viscount Astor's famed estate at Cliveden, arranged an unsuccessful screen test for her with Douglas Fairbanks Jr.
But he also introduced her, fatefully, to Mr Ivanov and Mr Profumo. Miss Keeler also had a West Indian lover, John Edgecombe, a petty criminal and film extra, whose actions, ironically sparked off the whole Profumo scandal.
Mr Edgecombe was involved in a shooting incident outside a flat - Stephen Ward's - in Wimpole Mews, Marylebone. It was alleged that he fired shots at her, but was acquitted on charges of shooting at her with intent to murder her or cause grievous bodily harm.
But he was convicted of having a firearm with intent to endanger life. He was sentenced to seven years.
However, Ms Keeler, who was due to give evidence at his trial, had gone missing. By now, March 1963, Westminster, and indeed the whole country, was teeming with rumours about Mr Profumo's presence at wild parties at Cliveden and his association with Ms Keeler.
Questions were asked in the house about the suspicious and intriguing circumstances surrounding the "missing witness", who had fled to Madrid, where she was actually tracked down by reporters.
Meanwhile, Mr Profumo was forced to make a statement to the Commons in March that year, in which he fiercely denied any impropriety whatever in his relationship with Ms Keeler and threatened libel writs on anybody who suggested otherwise.
His statement, which took no more than two minutes to read in a half-empty but rapt House, said: "I understand that my name has been connected with the rumours about the disappearance of Miss Keeler."
Indeed, he said, he and his wife, the late actress Valerie Hobson, had met her at Cliveden, and he had subsequently seen her "on about six occasions at Dr Ward's flat" in London.
"I last saw Miss Keeler in December 1961, and I have not seen her since. Any suggestion that I was in any way connected with or responsible for her absence from the trial is wholly and completely untrue.
"There has been no impropriety between myself and Miss Keeler. I shall not hesitate to issue writs for libel and slander if scandalous statements are made outside this House."
His assertion of a platonic friendship with Ms Keeler, which he said had ended in 1961, was accepted, incredibly, by the Cabinet. Downing Street described the matter as closed.
But MPs and newspapers remained sceptical. There were thinly veiled suggestions that Ms Keeler had been packed off to her hiding-place in Madrid to avoid an embarrassing cross-examination at the Edgecombe trial, so as to protect those in high places with whom she had cavorted, and also those who might have been guilty of treachery.
Finally, on June 4 1963, Mr Profumo resigned after confessing that he had lied to the House. It was at the time when Dr Ward was arrested and charged with living on immoral earnings. Dr Ward committed suicide after being found guilty of some, but not all, the charges.
But Ms Keeler's troubles were by no means over. In December 1963, she was jailed for nine months after admitting perjury and conspiring with others to pervert the course of justice.
This arose from evidence she had given at the trial, the previous June, of Aloysius "Lucky" Gordon, a Jamaican jazz singer. In her evidence, she had falsely denied that two other black men were present during an attack on her by Gordon.
Years later, in 1986, Ms Keeler was to revisit Cliveden and the famous swimming pool. She said: "I was just a 19-year-old girl having a good time. I loved every minute of it. But if I had known then what was going to happen, I'd have run off and not stopped until I had reached my mum."
She said Mr Profumo, who was introduced to her at Cliveden, chased her twice round the dining room, before finally stealing a kiss in the library. The following day, at the swimming pool, as the champagne flowed freely, Mr Profumo horsed around with Miss Keeler on his shoulders. It was at this point that Mr Ivanov came into the picture, with the fateful consequences that became history.
In 2001, Ms Keeler wrote a book in which she claimed that Dr Ward ordered her to sleep with Mr Ivanov and Mr Profumo in the hope she would pass on secrets. She also claimed that Dr Ward threatened to kill her when he thought she was about to expose his part in the spy network.
She also insisted that Sir Roger Hollis, the former head of MI5, was the mysterious "fifth man" in the 1960s spy ring that included Burgess, Maclean, Philby and Blunt.
And according to her version, Lord Denning, author of the Profumo report, refused to accept her evidence on the involvement of Dr Ward and Sir Roger.
"I went to Lord Denning looking for a way out of the mess I was in and he juggled with my life and, like a conjuror, made the truth vanish."
She made considerable sums from her memoirs, but this money was soon spent.
Although her name will forever be associated with the Profumo scandal, Ms Keeler disappeared from the scene and for years lived either at Westcliff-on-Sea, Essex, or at a dingy flat in Chelsea.
She was married twice and had two sons.