Diana trusted designer Catherine Walker so much that she didn’t ask to see sketches for this dress. She simply instructed Walker to select and make the gown for her 1989 state visit to Austria. The hip-hugging number features ruching down the center front seam and a front slit to the knee. Diana paired it with a diamond and emerald choker necklace, given to her by the Queen Mother.
Guide price: £30,000 to £50,000