When the Duchess of Cornwall stepped out in her first royal tiara it was just the third time the priceless headpiece had been worn in public.
Comprising brilliant-cut diamonds mounted in gold and set in platinum, it was made in 1911 by the high-class jeweller Garrard for the Queen's grandmother, Mary.
Queen Mary, known for her splendid jewels, wore the tiara for the Delhi Durbar, to celebrate the coronation of her husband, George V and the start of his reign as King and Emperor of India in that year.
Until Tuesday evening, when Camilla wore it to Buckingham Palace for a state banquet in honour of the King and Queen of Norway the tiara had not been worn in public since 1947.
It was lent to the Queen Mother for an official visit to South Africa, with whom it remained until her death, when it was passed to the Queen.
In June 1998 it was part of an exhibition of royal jewellery at the auctioneer Christie's.
When it was first made, the tiara was also topped with five Cambridge cabochon emeralds and also was occasionally worn with two diamonds from the Cullinan stone.
But the emeralds were removed by Queen Mary and made into another tiara - now owned by the Queen - and the diamonds became a brooch.