In a break with tradition, Prince William was the only blood prince to swear loyalty to the King during the historic ceremony.
After the Archbishop of Canterbury placed St Edward’s Crown on Charles’s head, William knelt before his father to give an oath of allegiance.
He said: “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.”
The heir to the throne then touched his father’s crown and kissed him tenderly on the cheek.
Charles, who looked emotional, nodded to William and said: “Amen.”
William also helped to clothe his father with the Stole Royal, a golden priestly scarf, during the ceremony. Charles was also presented and clothed with the Robe Royal, a long cloak.
The Archbishop said: “Receive this Robe. May the Lord clothe you with the robe of righteousness, and with the garments of salvation.
In previous coronations, dukes would have paid the homage to the monarch during the ceremony. Sticking to this tradition would have meant the Duke of Sussex, the Duke of York and the Duke of Edinburgh having to pleged allegiance to King Charles today.
However, it is understood that the King decided only William will carry out the pledge for his coronation.
Meanwhile, Prince Harry sat in the third row in the Abbey to watch the coronation take place. He attended the occasion alone, while the Duchess of Sussex and their two children remain in California.
In television footage, Harry was seen watching closely as the Archbishop placed the crown on his father’s head.
As the congregation paid homage to the new monarch, Harry was seen speaking the words: “God save King Charles. Long live King Charles. May the King live forever.”
After the ceremony, the newly crowned King and Queen will travel back to Buckingham Palace in the Gold State Coach, with William and Kate Middleton, as well as their children, following behind.
Working members of the royal family will later appear on the palace’s famous balcony to wave at the crowds who have gathered to watch.