Long-established London jewellers Hancocks return to the event after more than ten years.
Another well-established London jewellery specialist is Sanda Lipton, who will take to the fair this very rare silver-gilt ceremonial key from the office of the Groom of the Stole for William IV.
The key is dated 1833, but the position of Groom of the Stole dates back to 1660. He was an important person and, as head of the Royal bedchamber held the key - priced at £2300 - which opened every door in the palace. The 13th Marquess of Winchester, who owned this key, was the last to hold the office as it was abolished with Queen Victoria.