Despite putting family tensions aside to attend his father's coronation, Prince Harry's brief appearance left King Charles "disappointed," according to insiders close to the royal family.

Sources reveal that the newly crowned King of England was disheartened when his estranged son made a swift exit from the UK to return to the United States for his son Archie's fourth birthday, rather than remaining for the royal celebrations.

Although some royal family members were reportedly relieved by Harry's early departure, the King was "genuinely quite disappointed that he didn’t stay."

During a lunch following the coronation ceremony, the 74-year-old monarch expressed his feelings, thanking his three grandchildren, Prince George, Princess Charlotte, and Prince Louis, as well as acknowledging family members who were not present.

In front of the entire gathering, which included Prince William and Kate Middleton, the former Prince of Wales raised a toast to "those that weren’t there" and wished Archie a happy birthday "wherever he was."

An insider described the King's tribute to Harry and Meghan Markle's 4-year-old son as "a very sweet moment."

Before his family members even had the chance to greet well-wishers from the Buckingham Palace balcony, the Duke of Sussex was spotted boarding a plane at Heathrow Airport, en route to America where the former Suits actress was hosting a small celebration for their child.

"While Prince Harry joins the pomp and the pageantry over here, it's going to be a much quieter occasion for Meghan over in California, who will be bringing together some of her closest friends and family for birthday celebrations for Archie," said royal expert Omid Scobie, discussing the busy weekend.