The late Queen Elizabeth II's jewellery collection is the most impressive in the world, with everything from glittering tiaras to diamond-encrusted diadems, strings of pearls and more at her disposal.
READ: 14 of the Queen's most breathtaking jewellery and tiara moments
One of the rarest pieces in the Crown Jewels collection of 23,578 gemstones is the George IV State Diadem, officially known as the Diamond Diadem. George IV commissioned Rundell & Bridge to make the piece in 1820 for £8,216. It's estimated to be worth nearly £800,000 today and is one of the most symbolic crowns in the royal collection.
WATCH: Queen Elizabeth II's magnificent jewellery collection
The Diamond Diadem is one of the Queen's most recognisable crowns. It's present on British and Commonwealth coinage, postal stamps and banknotes - though it rarely makes an appearance in public.
The Queen has worn the diadem several times during her reign, namely to the first State Opening of Parliament of her reign in 1952, and on the journey to her coronation in 1953. It's particularly special because it's strictly reserved for sovereigns and Queen Consorts.
Which royal will wear the Diamond Diadem next?
The glittering diamond-encrusted piece is unlikely to make a public appearance anytime soon. The Royal Collection Trust states the diadem has only been worn by four queens since the 19th Century: Queen Victoria, Alexandra, Mary and Elizabeth II.
The monarch wore the Diamond Diadem for State Openings
A typically more feminine piece, King Charles III's wife, Queen Consort Camilla, is likely to be the next to wear the statement crown, rather than the monarch himself.
Royal fans could expect to see the 75-year-old royal wearing the heirloom for official State Openings, or at the upcoming coronation.
When Prince William eventually becomes King, his wife will inherit Camilla's title of Queen Consort. The Princess of Wales will then share the privilege to wear the prized jewels.
The royal crown is estimated to be worth nearly £800,000
The silver and gold-lined diadem features a narrow band edged with pearls, surmounted by four crosses pattée, and four sprays representing the national emblems of England, Ireland and Scotland - roses, shamrocks and thistles.
Set with 1,333 diamonds, including a four-carat pale yellow brilliant in the centre of the front cross, it's typically worn over a velvet cap, though Elizabeth II preferred to wear it by itself.
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