The iconic ivory bridal gown she wore for her majestic 1981 wedding to Prince Charles will be given to Prince William and Prince Harry later this month, as determined by their late mother's will.
The document stipulates that the dress should be given to her sons after Harry turns 30, which he will on Sept. 15.
The silk-and-taffeta lace dress, created by David and Elizabeth Emanuel, features a 25-ft. train and 10,000 pearls. In its day, it was as famous as the Alexander McQueen gown Kate Middleton wore for her 2011 wedding to Prince William.
In the 17 years since Diana's death, her brother, Charles Spencer, has been looking after the gown, along with a collection of clothing and some other personal effects.
In 1998, it became the centerpiece of the museum at Althorp, the Spencer family's estate in Northampton.
After more than a decade on display there, the dress has been taken down, and the impending relocation to London raises the prospect that it will be on public display in one of the capital city's royal palaces.
Last summer, a collection of royal dresses was on public display at Kensington Palace, where William and Harry have their respective private, official residences.
This includes, on loan from PEOPLE, a gown previously worn and owned by Diana.