In 1942, Prince George, Duke of Kent crashed his plane into the side of a Scottish mountain. This required no special explanation at the time, as the weather was poor and visibility low.
However, in keeping with the Duke's reputation, conspiracy theories have flourished.
One of the more extreme is that the Duke, who was thought to have sympathies with the Nazis, was assassinated by the British Secret Services.
He died a mere eight years after shaking off rumours of drug addiction and gay relationships - including with Nöel Coward - by marrying the beautiful Princess Marina of Greece and Denmark.
Five years after his death there was a famous auction of his belongings. And, in November 2009, there will be another, once again held by Christie's.
The sale will include a number of the Duke's personal possessions, with some of its 200 lots are expected to fetch £50,000 each (compared with £92,000 total for the 1947 auction).
Estimates are probably unreliable, however, as both Princess Margaret's and the Duke of Gloucester's belongings went for far more than estimated when auctioned in recent years; literally over 100 times for a few items.
Some of the items likely to have been underestimated include two pieces relating to Queen Victoria. A diamond brooch with the inscription Victoria R is estimated at £400, while £700 is expected for a necklace containing photographs of the Queen, Albert and their children.
Remarkably, there is a painting by Queen Victoria herself of her young daughter, Louise - albeit a copy of a more accomplished artist's work, Franz Winterhalter - estimated at £15,000.
Along with the art and jewellery, there is some antique furniture, most notably the chair in which the Duke of Kent sat for his brother's Coronation as George VI after his other brother, Edward, abdicated.
The chair is finished with gold, and valued at up to £30,000.
Elsewhere, listed at £30,000-50,000 and auctioned especially for the Soldiers', Sailors' Airmen and Families' Association, is a beautiful silver model of the Bentley Jackson Special (or Mother Gun) presented to HRH Prince Michael of Kent on his retirement as President of the Institute of the Motor Industry.
Also expected to sell for £30,000-50,000 is a semi-spherical George II silver punch bowl, marked Anthony Neme 1731 on its base.
The Christie's auction will take place on November 20 at King's Street, London.