Queen Camilla Makes Her Debut in a Historic Crown for King Charles' First State Opening of Parliament

Queen Camilla is dazzling in a crown — just like queens to come before her.

Queen Camilla joined King Charles at the first State Opening of Parliament to take place during his reign on Tuesday. While King Charles wore the Imperial State Crown during the ceremony (marking his first time wearing a crown since his coronation in May), his wife was sparkling in the Diamond Diadem for the first time.

Also known as the George IV State Diadem, the headpiece was made for the coronation of King George IV in 1820 — and it's what the monarch wore (along with a large purple velvet cap) on his way to Westminster Abbey for his crowning ceremony.

Since King George IV, the Diamond Diadem has been worn by every British queen, whether they reigned or were consorts: Queen Adelaide, Queen Victoria, Queen Alexandra, Queen Mary, Queen Elizabeth (the Queen Mother) and Queen Elizabeth.

The accessory was closely associated with Queen Elizabeth, King Charles' mother who died in Sept. 2022. She wore the Diamond Diadem for the first time in public at her first State Opening of Parliament in 1952 (before she was formally crowned at her coronation). At her coronation in June 1953, Queen Elizabeth wore the headpiece on her way to Westminster Abbey for the crowning ceremony.

Queen Elizabeth also wore the diadem on the way to most State Openings of Parliament (though she swapped it for the Imperial State Crown for the service) and in photographs including those used for British and Commonwealth coinage, banknotes and postage stamps.

The Diamond Diadem is set with 1,333 diamonds, including a four-carat pale yellow brilliant in the center of the front cross, according to the Royal Collection Trust, while the band is set with pearls. There are four crosses alternating with four sprays representing the national emblems of England (roses), Ireland (shamrocks) and Scotland (thistles).

Queen Camilla paired the diadem with the ultimate recycled outfit: her coronation dress! The white gown was designed by Bruce Oldfield and features personal embellishments including florals, a crown, the names of her children and grandchildren and even embroidered versions of Camilla's two dogs, Beth and Bluebell!

The State Opening of Parliament began with King Charles and Queen Camilla taking part in a procession by horse-drawn carriage from Buckingham Palace to the Palace of Westminster. The royal regalia — including the Imperial State Crown, the Great Sword of State and the Cap of Maintenance — traveled in their own coach.

Following royal tradition, King Charles stepped into the Palace of Westminster through the Sovereign's Entrance and then headed to the Robing Room, where he put on the Parliament Robe of State and the Imperial State Crown.

During the ceremony, King Charles delivered the King's Speech, which is written by the government and contains an outline of its policies and proposed legislation for the new parliamentary session.

King Charles previously wore the Imperial State Crown at his coronation on May 6. Although he was officially crowned with the St. Edward's Crown, which is only used to crown a new king or queen during the coronation ceremony, he swapped it for the Imperial State Crown toward the end of the service.

The Imperial State Crown, which dates back to the 1937 coronation of King George VI, is made of gold and set with 2,868 diamonds, 17 sapphires, 11 emeralds, 269 pearls, and four rubies.

Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more!

Since Queen Elizabeth's death, Queen Camilla has sported a number of accessories closely related to the late monarch.

Last month, Queen Camilla visited Mansion House with King Charles to take part in longstanding traditions marking a new monarch's first visit to the City of London (the historic square mile that joins 32 boroughs to make up Greater London) in their coronation year. The outing marked a royal first as she made her debut in the Girls of Great Britain and Ireland tiara. Queen Elizabeth wore the accessory numerous times throughout her 70 years on the throne, including in depictions of her on some British and Commonwealth banknotes and coins.

At the same event, Queen Camilla wore her mother-in-law's sparkling necklace and bracelet set that the late royal received as a 21st birthday gift. The then-Princess Elizabeth marked the milestone occasion in South Africa, and in a speech broadcast from Cape Town, she dedicated her life to the service of the Commonwealth.