The Diamond Diadem, also known as the King George IV State Diadem, is one of the British monarchy’s most recognisable pieces of jewellery.
It was ordered from the jeweller Rundell in 1820, and it was completed in May 1820. The design, probably made by their chief designer Philip Liebart, incorporates the national emblems of England, Scotland and Ireland. The bill came to £290 for the setting and £800 for the hire of the diamonds. It does not appear that the diamonds were ever returned to the jewellers, and a larger bill for £8,216 later appeared in the Privy Purse accounts.1
King George IV wore the diadem during the procession to his coronation, but it has been worn by every Queen consort and regnant since Queen Adelaide. It was altered for Queen Victoria in 1838, for Queen Alexandra in 1902 and for Queen Elizabeth (the Queen Mother) in 1937. Queen Elizabeth II wore the Diamond Diadem for the first time during her first State Opening of Parliament in 1952. She also wore it on her way to her coronation in 1953 and for subsequent State Openings of Parliament.2
She was also portrayed wearing it on coins, stamps and several artworks.