The coronation of King Charles III will take place at Westminster Abbey on Saturday, May 6, with the service conducted by the Archbishop of Canterbury.
The Crown Jewels will play a starring role during the religious service and treasures on display will include Sovereign's Orb, the Golden Spurs and the Sovereign's Ring.
Charles will be officially appointed as King and wear two crowns to mark the historical moment, as well as a number of spectacular robes steeped in tradition.
But what crowns will they be and how much are they worth? Here is everything we know:
What crown will King Charles III wear at his Coronation?
As per royal tradition, Charles will be officially crowned as King with St Edward's Crown during the Coronation.
This will be the first and only time that Charles, 74, will wear the 17th-century crown.
It was recently removed from the Tower of London to be resized for the King ahead of the monumental service.
Charles will then switch to the lighter Imperial State Crown at the end of the ceremony to leave the Abbey, as is custom.
What is the value of the St Edward's Crown?
St Edward's Crown is made of solid gold, with a velvet cap and ermine band.
It weighs nearly five pounds in total and bares 444 gemstones, including rubies, sapphires, garnets and tourmalines.
Although the exact value of the crown has been heavily debated over the years, experts have speculated that it is worth between £3 billion and £5 billion.
What is the history of St Edward's Crown?
St Edward's Crown was made for King Charles II in 1661, as a replacement for the medieval crown that had been melted down in 1649.
The original crown was thought to date back to the eleventh-century royal saint, Edward the Confessor.
St Edward's Crown is only used during coronation ceremonies and was worn by Her Majesty Queen Elizabeth II at her coronation in 1953.
The late monarch revealed in 2018 that she also had the crown resized to fit her head.
In an interview with the BBC, she said: "You see, it's much smaller isn't it? It would have been up to about there when my father wore it."
St Edward's Crown features on royal cyphers and the Royal Mail logo is also based on it.
What is the value of the Imperial State Crown?
The Imperial State Crown, or Crown of State, is the crown the monarch exchanges for St Edward's Crown at the end of the coronation service.
It is also used on ceremonial occasions, such as the State Opening of Parliament, with the late Queen joking it was her "party hat".
The exact value of the Imperial State Crown has been the subject of debate for years, but according to financial researchers at Cashfloat, it is estimated to be worth £5 billion.
The crown is composed of gold and set with some of the most famous jewels, including 2,868 diamonds, 17 sapphires, 11 emeralds, 269 pearls and four rubies.
These include the Black Prince's Ruby, the Stuart Sapphire and the Cullinan II diamond.
The current version of the Imperial State Crown was made for King George VI's coronation in 1937, replacing the crown that was created for Queen Victoria in 1838.
What crown will Camilla wear at the King's coronation?
Camilla will be crowned in Queen Mary's crown, which has been altered to include some of the late Queen's jewels, such as the Cullinan III, IV and V diamonds.
These were part of Queen Elizabeth II's personal jewellery collection for many years.
There was controversy surrounding the potential use of the Koh-i-Noor diamond, seized by the East India Company in 1849 and presented to Queen Victoria, and which featured in the late queen mother’s crown in 1937.
Before the announcement that it would not be used, India said "brings back painful memories of the colonial past".
