What crown will Camilla wear during the coronation, and why is it controversial?

While King Charles III will officially be crowned sovereign at the coronation May 6, his wife, Camilla, will also be anointed as the queen consort.

For the ceremony, Camilla has decided to wear Queen Mary's Crown, which marks the first time since the 18th century that a consort will use an existing crown for their coronation.

According to Buckingham Palace, the decision was made in the interest of sustainability, as traditionally, a consort commissions a new crown.

But the choice of Queen Mary's Crown also notably avoids the Kohinoor diamond, which is set in the Queen Mother's Crown. The 105-carat stone is one of the largest cut diamonds in the world and comes with a dark history.

The diamond is believed to have been mined in India in the 13th century, then passed through the hands of several dynasties. When the British annexed Punjab in the 1849, it is believed that a regional ruler was coerced into giving the diamond as a gift to the British.

In October, a spokesperson for India’s ruling Bharatiya Janata Party said that including the diamond in the ceremony would bring "painful memories of the colonial past.” 

To prepare for the coronation, Queen Mary's Crown went through several changes, including the removal of a replica of the Kohinoor and the addition of the Cullinan III, IV and V diamonds. These diamonds were used as brooches by the late Queen Elizabeth II.

However, the Cullinan diamond also has a history steeped in colonialism. The diamond hails from South Africa and had been found in a region colonized by Dutch settlers who were hostile to local tribes.

The discovery of the diamonds led the British to flood South Africa, and they attempted to annex the regions, leading to the Anglo-Boer Wars which ended around 1902.

In 1905, the Cullinan diamond was found in a mine and was the largest uncut diamond ever discovered. In 1907, a British-controlled government bought the diamond and gifted it to King Edward VII for his 66th birthday after the conflicts.

In addition to wearing the Cullinan diamonds in her crown, Camilla's coronation robe also pays homage to Queen Elizabeth II, who died in September.

Camilla's Robe of State, which is worn when arriving to Westminster Abbey for the coronation, was originally made for Queen Elizabeth for her ceremony in 1953.