ON THE first day of the daylight blitz on London, Joseph P Kennedy walked with an aide through the dusk into Green Park. He gestured through the trees at the dark shape of Buckingham Palace, and said: 'I'll bet you any sum, at odds of five to one, that Hitler will be sitting over there in two weeks.'

At that moment, though he could not know it, Joe Kennedy's huge ambition for his own career was thwarted. His miscalculation about Nazi power, and his profound pessimism about Britain's ability to resist it, were to lead him to humiliation and disgrace. Few previous ambassadors had been so confident in their social and political expectations on arrival. He had hoped to return as Roosevelt's designated successor; instead he was exploited, then shunned, by FDR. His presidential ambitions would be reborn in his four sons, with many false dawns as they in turn were killed or maimed, but he himself would remain in the shadows which began to fall across him in that summer twilight of 1940. Yet he was in many ways the most remarkable Kennedy of them all.

He lived by the telephone. With it he could move stock prices halfway round the world; he could trade gossip with the most powerful men of his time. He could fix city bosses and square press tycoons. 'He could see anybody he wanted to see; he could reach anyone he wanted to reach,' remembers the veteran Boston journalist John Galvin, recruited by Joe in 1946 to publicise his second son's congressional campaign. Another Boston Irish-American, Speaker Tip O'Neill, says: 'Money was the mother's milk of politics. Joe knew that before anybody else.' Today, 23 years after his death, when a new book about his children appears every week, Joseph P Kennedy is largely forgotten. Yet it was he who 'kept the blowtorch on them' to excel, in the memory of the youngest child, Teddy. For Joe Kennedy it had to be 'the outhouse or the castle; nothing in between]'

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He had the ability to capture the castle for himself, but he was a cocktail of contradictions. He had a genius for making money, but despised the business class. He shunned war and physical conflict, yet produced children who triumphed over pain and fear regardless of cost. He was a priapic hunter of women - anywhere, any time - but an intense family man. And he had a rare gift for publicity, but was least good at selling himself.

As his wife Rose uncomprehendingly enters her 103rd year at the Kennedy 'compound' in Hyannisport, Joseph Kennedy's papers are stored in his son's presidential library. They are not yet in the public domain, and, in the mordant words of Kennedy's last biographer, they 'are not likely to be open to the public until long after the presidential tenure of some Kennedy yet unborn'. The trail is hard to follow through the thickets of legend.

It has grown fainter with the waning of human life. Kennedy's contemporaries have all gone. The last of the men who served him in Hollywood, Arthur Poole, is almost 98 years old. In the last year, five of those who knew him well have died: Jimmy Roosevelt, eldest son of another president, still chuckling in a dry whisper on his deathbed about the old tempter Joe; two very different men who loved Joe's daughter Kathleen, the Washington political columnist John White and the English playwright William Douglas Home; the Hollywood producer Sam Marks; and Harvey Klemmer, a candid friend as well as a loyal helper, who knew where the bodies were buried. The friends and tutors of the Kennedy brothers have grown old in their turn - J K Galbraith, who taught them; Frank Waldop, who gave them jobs. Soon the direct memory of Joe will rest with his children and their children, who loved him unreservedly.

ONLY ROSE KENNEDY, in the secret harmonies of her memory, remembers how it all began, in East Boston, where this lanky red-haired grandson of an Irish immigrant was born in 1888 into the tightly-knit family of a liquor merchant turned state senator.

Doors opened for young Kennedy, with his prowess on the baseball diamond and his ability to make money fast. But not all. He felt snubbed by the old Protestant elite in not gaining selection for the cherished final clubs at Harvard, and he never forgot. The only thing those people understood, he said, was money. Thirty years later he snarled to one of the young lawyers at the Securities and Exchange Commission, Milton Katz, that 'you have to take everything' from the business elite, 'even the gold from their teeth'. By the age of 25, Joe Kennedy was styling himself 'the youngest bank president in the world' and had won the hand of Rose Fitzgerald, daughter of Boston's garrulous mayor John F Fitzgerald, known to those who liked him as Honey Fitz.

The marriage endured until his death, despite the couple leading separate private lives. Joe and Rose almost came to the point of formal separation after she had borne five children in six years, but she returned, fortified by the consolations of her religion and frequent shopping trips abroad. Joe was generous with her, and he could afford to be. In the 1920s he made one fortune after another, always spotting the trend - liquor, automobiles, movies. On Wall Street he found it easy to play the market, boosting stocks with his allies until the moment came to unload them on the gullible. He wanted to make this easy money fast, he said, 'before they pass a law against it'.

Then he bought an ailing British film company, FBO, and moved on, to Hollywood, where he became a big producer of low-budget films, learning techniques of publicity he would never forget, and losing his head to the movie queen Gloria Swanson. At the height of their affair Kennedy had flaunted Swanson, even taking her on an Atlantic crossing with his wife. Nearly 50 years later Rose Kennedy was still ingenuous about the trip, telling the biographer Doris Kearns that 'I knew I never had a thing to worry about and I only felt sorry for poor little Gloria.'

Kennedy remained an avid pursuer of women. 'He was a big, handsome, well-muscled, charming guy,' his former aide Harvey Klemmer recalled, a few weeks before his death in Florida earlier this year at the age of 92. 'He liked women and women liked him. But he regarded them as a kind of food - to be consumed.' His staff were expected to procure for him; a chore which was repeated for his second son. Neither the dignity of ambassadorial office nor the self-respect of late middle age ever got in his way. His sons became used to him as a sexual competitor. 'The ambassador prowls at night,' Jack would warn girls visiting the Kennedy estates at Palm Beach and Hyannisport. The role of the sexual predator was one he handed on to his older sons, Joe Jnr and Jack. 'You must remember,' says Jack's friend William Walton, who visited the compounds often in the Forties and Fifties, 'there was no tradition of monogamy in that family.'

That was true for the sons, but Kennedy went to extreme lengths to protect his daughters' virtue. Kathleen Kennedy told her startled suitor John White that her father had a dossier on him, and that she had to report her doings to him each day. Joe relished the control that his money gave him. He was generous and loving, but he found it hard to let go. Even when his second son was a US congressman, Joe methodically worked through his staff until he found one who was prepared to be his eyes and ears in Washington. As the sons progressed through school and Harvard and toured the world at his expense, Joe kept up a barrage of advice and encouragement, pressing their letters on his friends. Trust funds were settled on them at an early age. They never needed to work in his enterprises, and they may never have fully known what these were. It was not always easy to find out.

In the Twenties, rumour had it that Kennedy was a bootlegger, importing and selling illicit liquor. Doris Kearns, the only historian to have access to Kennedy's papers, found scant evidence there to support the claims made by, among others, the gangsters Frank Costello and Meyer Lansky of large underworld deals. But Kennedy went into the Prohibition era with large stocks of liquor from his father's stores, and on the day it ended he had three lucrative franchises for British whisky and gin, a company to important them, and a network of retailers already in place. It was the work of a man who knew well where the subterranean rivers of illicit booze had run during Prohibition, but kept the knowledge close. His papers guard it still.

In any event, the liquor profits were a mere aperitif for the fortune Kennedy made on Wall Street. In February 1929, with the market still rising in response to the election of Herbert Hoover, Kennedy began to sell out, for cash or bonds. Arthur Poole, the last survivor of his financial team in the Twenties, remembers the incredulity of Kennedy's boardroom colleagues at Paramount Pictures when he told them that their stock was over-valued, and that he proposed to sell it short in the market. 'They all said, 'Don't do that; you'll lose your shirt. Things are going wonderfully well.' '

By selling short (borrowing the stock, selling, waiting for the price to fall and then buying back at a far lower price the stock to be returned), Kennedy took the Paramount share price down from dollars 35 to dollars 6. When the October crash came, Kennedy was one of the few who kept his shirt, and more. As the bear market which he had helped to create intensified, Kennedy became involved in some of the most destructive speculation of the time, joining other bankers in a ring artificially boosting stocks by buying from each other and then selling out once enough 'suckers' had bought in.

This was an unlikely background for a public man, but Joe Kennedy saw no incongruity. He sensed that the response to the crash would bring a greater role for governments, and he became Franklin Roosevelt's ardent supporter, raising dollars 200,000 for the 1932 presidential campaign. He correctly saw that Roosevelt would save capitalism, not destroy it, and would have been happy, he said, to gamble half his fortune on the New Deal if that meant he could keep the other half. He wanted power as well as security, but the reformers around Roosevelt were suspicious of him. Roosevelt had been in power two years before Joe was given a job, and it was greeted with howls of protest in Washington. The poacher was asked to turn gamekeeper, and chair a new Securities and Exchange Commission to regulate Wall Street. It would mean policing the very practices out of which his own fortune had come, and he did it with alacrity. 'He knew which way these jokers worked, you see,' recalls Frank Wardrop, who was then editor of the Washington Times- Herald. 'So he thought he could sort them out. And he did.'

Always a man of prodigious appetites, he now wanted power for himself. In a ghosted book titled I'm For Roosevelt, the self-styled 'Father of Nine' disclaimed personal ambition and called for four more years of FDR. The President rewarded him with warm words and a second-rank appointment, outside the cabinet. He was made chairman of the US Maritime Commission, charged with the regeneration of America's merchant marine. Kennedy was unabashed. 'It's not what you are, but what people think you are,' he always said. And he made sure that the commission's economic survey secured dramatic publicity in the Hearst newsreels and newspapers. One of the men who turned it out for him, Harvey Klemmer, was astonished to find it 'treated like the second coming of Christ'. No opportunity was lost to build up his achievements in his two government posts, and he now craved another. By the end of 1937 Roosevelt had three years to run in his second and (it was assumed) final term. Kennedy dreamed of succeeding him - as the first Catholic president.

There was one post which offered both social status for the brash Irish-American outsider and a high international profile: Ambassador to the Court of St James. Kennedy lobbied hard for it, through FDR's worldly son Jimmy, who had already done him favours in securing British liquor franchises. Kennedy did not expect to stay long. His style was to move in, analyse, recommend, and move on, with profits and/or publicity augmented. Eighteen months in the embassy might be the perfect coronet for the public career of Joe Kennedy, contender for the Democratic nomination

in 1940. Instead, his London years were to

bring disaster.

THE POSTING began well, in March 1938. 'The regular diplomats were absolutely terrified of Joe,' the embassy secretary Page H Wilson recalls, 'but the press went absolutely ape over the entire family. I don't think there was a day in a month that there wasn't a photograph of the Kennedy family.' Teddy opened the Children's Corner at the Zoo. Even the retarded eldest daughter Rosemary was presented at court and appeared in the newsreels. Joe Jnr, Jack and the next sister, Kathleen, cut a swathe through London society.

The only problem was Hitler. When Joe Kennedy arrived in London, Hitler's designs on Austria and Czechoslovakia were apparent for all to see. They gave Kennedy few qualms. He had no desire to see his country embroiled in any kind of European war, and the best way to avoid it, he argued, was to follow through the appeasement policies of Neville Chamberlain. The two became a mutual admiration society, with Kennedy privy to Cabinet secrets in exchange for his support in public speeches.

The ambassador had no faith that the British cause would prevail in a war with Germany, and for ancestral reasons he had little faith in the British Empire. He saw it like a business problem. Germany, if you believed the estimates of Colonel Lindbergh, as Kennedy did, was now the stronger military power. It would be better to cut a deal than be taken over. The moral case against the Nazis meant little to him. Harvey Klemmer, whom he had brought from the Maritime Commission, knew him to be a casual anti-Semite ('Individual Jews are all right, Harvey, but as a race they stink - look what they did to Hollywood'). Now Klemmer's reports back from Germany on the repression of the Jews were dismissed. 'They brought it on themselves,' Kennedy said, and in a confidential meeting with the German ambassador, Von Dirksen, he said that he 'understood our Jewish problem completely'. After the Kristallnacht outrages, Kennedy's views changed, but up to the outbreak of the war he hoped desperately that the Germans could somehow be bought off. Nor did his tone change thereafter. Home on a visit in East Boston (not a notably pro-British locality), he said, 'There's no place in this fight for us.' The three months that elapsed before he made a tardy return to London allowed British resentment to come to the boil.

Kennedy had tried hard to be popular in Britain, and he unfailingly complimented the nation's tenacity, even if he thought it doomed. Now his stock had fallen. A 'Kennediana' file circulated in the Foreign Office, recording Joe's rumoured words and deeds. He told more than one journalist his dismissive view of Winston Churchill, the new power in the British government: 'Never trust a man who is always sucking on a whisky bottle.' As Churchill established his own correspondence with Roosevelt, and the President tried to keep his options for aiding the democracies open, Kennedy was first sidelined, then undermined.

The Kennediana file contained allegations that Joe was playing the stock market, using his insider knowledge. No one knew for sure how much information he had on British plans to liquidate American security holdings to raise cash for war supplies. Klemmer remembered him on the phone from his English country retreat, yelling instructions down the phone to Johnny Burns, who handled his stocks in New York, but not the stocks involved. The mud stuck. He was 'a very foul specimen of double- crosser and defeatist (who) thinks only of lining his own pocket,' said Lord Vansittart, the senior Foreign Office figure most clearly identified with opposition to appeasement. And his business dealings were insensitive. When he had come to Britain he had kept his whisky company, Somerset Imports, in full operation. Klemmer, the attache from the Maritime Commission, was charged with commandeering precious cargo space on the perilous convoys for the ambassador's whisky. 'Using the prestige of the embassy,' he remembered, 'we got space for 200,000 cases, and it got so bad that a friend in the Ministry of Shipping came to see me and said, 'You'd better go easy because one of his competitors is threatening to raise a question in Parliament about the improper activities of the American embassy.' So we pulled our horns in a little after that.'

In their eagerness to trap Kennedy, the British security services had his phones bugged. Embassy cars were stopped on a pretext and covertly searched. The Charge d'Affaires, Herschel Johnson, was bombarded in Kennedy's absences with dark hints about the leaking to the Germans of the ambassador's cables to Washington. On 20 May 1940, just days before Dunkirk, the British sprang their trap. Tyler Kent, a cipher clerk at the embassy, was arrested on a charge of stealing almost 2,000 of its top-secret telegrams. The record of Kent's interrogation by Kennedy before he was handed over to the British has been uncovered by historian John Costello. The ambassador's fury is palpable. He had to admit to Roosevelt that their secret correspondence had been filched and decoded; he could not guarantee the security of the embassy's communications. He had been neatly stitched up by Churchill, who could feel sure that the most dangerous opponent of American involvement in the war had been discredited.

JOE KENNEDY now ached to return to his family back home. Roosevelt was bullied and threatened. When the night bombing of London began, the ambassador took himself at 4pm each day to a rented mansion in the country. The ruling circles which had welcomed him and been charmed by his vibrant children began to shun him. The present Duke of Devonshire, whose older brother Billy Hartington was to marry Kathleen Kennedy in 1944, remembers that 'when he pushed off to somewhere in Surrey to avoid the bombing we didn't think much of that, no. We thought if we could face it and not think much of it, so could he.'

He returned home for good in October, telling Klemmer that he was going back to tell the American people 'that that crippled son of a bitch in the White House is going to drag their kids into the war.' He did no such thing. When the Boeing Clipper touched down at the New York terminal, he was whisked away with Rose to see the President, encouraged to pour out his frustrations, cajoled and flattered.

No one knows quite how the Roosevelt magic worked, but Kennedy went out and paid dollars 20,000 of his own money for radio time. He urged the nation to stay out of war, mentioned his own 'nine hostages to fortune' - and endorsed Roosevelt. His wilting political career might have been saved even then, but a few days later he blew it away forever with some remarks in Boston which he thought were off the record. 'Democracy all done in Britain, maybe here' was the headline. It was Kennedy who was all done. His daughter Kathleen phoned her friends: 'Please cheer Dad up. He thinks his life is over.'

The foreboding with which Kennedy had greeted the war was personally justified. At first he could play the patriarch at home. 'He's always presented as a stupid money-making capitalist,' remembers William Walton, who is now, aged 82, an artist in New York. 'Well, he was all those, but he was also very bright, and quite intellectual in many ways. Not the conventional picture. Nor was his role in the family. He was home more than I expected. And he had a far greater role in his children's lives than their mother did.'

Joe's plans for the family were boundless; again, they were destroyed when America went to war. His eldest son, Joe junior, to whom he had transferred all his political hopes, was blown to pieces over East Anglia on a secret bombing mission. His daughter Kathleen married Lord Hartington, a Protestant, to the great anguish of Rose, whose simple piety decreed that mixed marriages were made in hell. Within weeks, Hartington too was killed in action. In another cruel twist, Joe had had the retarded Rosemary lobotomised in 1941, neither consulting Rose nor telling her afterwards what had gone wrong. Rosemary survives in body to this day, but the pretty, gentle creature whom the family had cherished in their competitive midst was gone.

Jack, the detached, ironic second son, was injured in the Pacific but survived to become the family standard-bearer. Joe submerged his own ambitions, and even his personality, in Jack's campaigns. By 1957, Joe was estimated to be one of the dozen richest men in the United States. He did good works for charity, often anonymously, and he would go anywhere - even deep into the underworld - to help his second son become president.

When that bright day dawned, Joe Kennedy was on the rostrum as the Inaugural Parade rolled by. As the President passed, Joe raised his hat to the young man who had always puzzled him, and Jack Kennedy rose awkwardly in the limousine to doff his own hat in reply. The older man could be forgiven for a moment of melancholy. Twenty years before it had been his hour, and he had failed the test. But the family had captured the castle in the end.

Phillip Whitehead is the co-producer with Elizabeth Deane of 'The Kennedys', a four-part series which begins on ITV on Tuesday at 10.40pm.