Prince William had a pretty important role to play at the coronation as he pledged his allegiance to the new King. During the ceremony, he recited: "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."
Charles appeared to get emotional during the touching moment that he shared with his son, and he shared some sweet words with William, the heir to the throne. As you can see in the video below, Charles said: "Thank you, William," after his son pledged his allegiance. After his pledge, William placed his hand on the crown, and also bent down to give his father a kiss on the cheek.
In a break with tradition, the Prince of Wales was the only blood prince to pay homage during the service, with his brother, Prince Harry sitting in the third row to witness the historical moment.
William wasn't the only royal that Charles shared a sweet moment with during the historic ceremony as he exchanged comforting looks with his wife, Queen Camilla, as they were crowned at their joint coronation service. Later, Camilla, 75, was seen looking over at her husband proudly after she was crowned with Queen Mary's Crown by the Archbishop of Canterbury.
There were plenty of sweet moments throughout the day, including Princess Charlotte proving to be a protective sister over her younger brother, Prince Louis, as she held onto his hand as they entered Westminster Abbey.
Princess Anne also offered a helping hand to her husband Tim, after she spotted him struggling during the service. As the 68-year-old attempted to grab his glasses, Anne leaned over to help him out asking "Can you read this?" as she showed him the order of service. The Princess Royal was dressed in her Blues and Royals uniform for the event.
And as ever, Prince Louis stole the show with his facial expressions throughout the day. During the service, he was spotted yawning, looking up distractedly towards the ceiling, and pointing out things of interest to his sister Princess Charlotte, eight.
One moment that was unseen during the coronation was a private lunch that the King and Queen hosted for members of the family, although Prince Harry had to make a dash back to the airport, therefore missing the moment.
The three-day weekend is far from over as on Sunday, there will be the Big Lunch, where members of the Royal Family will head out across the nation to visit street parties being held in the new King's honour.
During the evening, there will be a concert held at Windsor Castle, which will see the likes of Take That, Katy Perry and Lionel Richie performing. Freya Ridings had been scheduled to make an appearance, but was forced to drop out for health reasons - you can find out who's replacing her here.
Finally, on the Monday, there will be a push across the nation to join volunteering projects. Buckingham Palace said the Big Help Out on Monday will "highlight the positive impact volunteering has on communities across the nation".
A palace spokesperson said: "In tribute to the King's public service, it will encourage people to try volunteering, and join the work being undertaken to support their local areas.
"The aim of Big Help Out is to create a lasting volunteering legacy from the coronation weekend."