Valentino's honourary President and long-term friend of Princess Diana, Giancarlo Giammetti has posted a throwback picture on his Instagram account of the late Princess enjoying a holiday onboard a yacht in 1990.
In the never-before-seen pic, Diana is joined by Rosario Saxe-Coburg, who is married to Prince Kyril of Bulgaria and a young boy (who could be an eight-year-old Prince William) on the deck of Valentino's T.M.Blue One yacht.
"Summer is here TBT princess Diana on the TMblue 1990 #princessdiana #rosariosaxecoburg" wrote Diana's long-term friend.
The Princess, then aged 29, is seen wearing a printed two-piece swimsuit with a purple shirt tied over the top and a dark pair of sunglasses.
Diana was said to have loved spending time at sea as it was one of the few places she could relax away from the pressures of her very public life.
The mother of Prince William, 32, and Harry, 29, died in a car crash in Paris on August 31, 1997.
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