The inimitable style of Diana, Princess of Wales – from her ’80s power silhouettes as a senior royal to her move towards sleek tailoring as an independent activist in the ’90s – has been much documented. But, while Lady Di’s eveningwear – including the midnight-blue velvet off-the-shoulder Victor Edelstein gown she wore to dance with John Travolta at the White House in 1985, and the form-fitting Christina Stambolian LBD she wore after Prince Charles publicly confessed his affair with Camilla Parker-Bowles in 1994 – are ingrained in the public psyche, her off-duty looks are of equal merit.