Ronald Ferguson, the former royal polo manager and father of Sarah, Duchess of York, has died of a heart attack at 71, it was announced yesterday.
The major had been treated for prostate cancer and was in a Hampshire clinic for most of the past six months.
He was visited by his daughter, former wife of Prince Andrew, on Sunday before she left for a trip to Australia promoting the WeightWatchers organisation; she was told of his death when her flight stopped at Bangkok.
The Queen sent a private message of condolence, Buckingham Palace said. Prince Andrew was said to be deeply saddened, as was Prince Charles, for whom the major acted as polo manager for several years.
Andrew Ferguson, his son by his second marriage, said in a statement: "He never grumbled or moaned about his illness, he just got on with life.
"My father did marvellous things for hundreds of people, not just with his help for polo and cricket clubs, but with his tireless support for prostate cancer charities."
Nicknamed the galloping major - a title used for his autobiography - Ronald Ferguson proved as ready as his daughter to live up to a slightly undignified image. His career and reputation were damaged by tabloid exposés of his private life. Major Ferguson was spotted by the royals when, as a young officer in the Household Cavalry, he captained the Sovereign's Escort during a Trooping the Colour parade on the Queen's official birthday. Reportedly he was told by the monarch when his horse nearly pranced in front of her: "Back a bit, Ron - it's me they've come to see, not you."
He subsequently became polo manager to the Duke of Edinburgh and then his son.
It was Sarah Ferguson's short-lived marriage that thrust the major into the limelight. In 1988 he was photographed leaving a London massage parlour, an escapade that cost him his job as manager of the Guards' Polo Club.
Eight years later he was caught again when 34-year-old Lesley Player described their relationship in the Sunday papers. That led to him quitting as sponsorship organiser for the Royal County of Berkshire Polo Club.
The major once said: "I am nobody, nobody at all. I just happen to be the father of the Duchess of York. I mean, that doesn't make me terribly important does it?"
The duchess was due to cut short her visit to Australia and is expected home this week, though she will carry out engagements first. "This is exactly what the major would have wanted. He was very much in the mould of the show must go on," a family friend told reporters.