1,333 diamonds are set in silver and gold on this diadem, which incorporates the national emblems of the thistle, rose and shamrock.  It was created for George IV to wear on his coronation day in 1821.The diamonds were hired, rather than purchased, for the coronation, as was conventional at that time. However, George IV decided to keep the diadem after the event, and settled the bill for a little over £8,000.

In the following reign the diadem was worn regularly by Queen Adelaide, consort of William IV, and this established a tradition of feminine wear. Queen Victoria wore the piece for many paintings and photographs – as well as on several early postage stamps, including the Penny Black.  The diadem has since passed via Queen Alexandra, Queen Mary and Queen Elizabeth to Her Majesty The Queen, who memorably wore it on the way to Westminster Abbey for her coronation in June 1953.