So, what will his duties entail? According to the coronation liturgy shared by the Church of England, the Prince of Wales will present the king with the Stole Royal and the Robe Royal during the ceremony at Westminster Abbey in London on May 6.
As the church's website noted, the Stole and Robe Royal "represent what The King, as Sovereign, has been given by God." Just as how Queen Elizabeth II had a stole made for her coronation in 1953, King Charles III is having a stole commissioned for his big day. According to the website, the scarf will feature "significant Christian iconography, including the gridirons of St Lawrence," and palm branches.
The robe itself also has quite a bit of history. According to the Royal Collection Trust, the item—which is made of gold cloth and features patterns of "foliage, crowns, fleur-de-lis and eagles with colored roses, thistles and shamrock"—was first made for the coronation of King George IV.
After Prince William presents the Stole and Robe Royal, the Bishop of Durham will vest the king in the stole and then Prince William, the Baroness Merron and Assisting Bishops will clothe him in the robe.
And these won't be Prince William's only tasks. After the king is crowned, the Prince of Wales will kneel before him and recite the Homage of Royal Blood. According to the coronation liturgy, he will say, "I, William, Prince of Wales, pledge my loyalty to you and faith and truth I will bear unto you, as your liege man of life and limb. So help me God."
But Prince William isn't the only one in the royal family to have a role during the coronation. His 9-year-old son Prince George, whom he shares with Kate Middleton, will also take part by serving as one of the eight Pages of Honor.
"His parents are very excited and delighted that he is a page," a spokesperson for the Prince and Princess of Wales told People on April 14. "It's something that his parents have thought long and hard about and are very much looking forward to—and I'm sure George is too."