As his father King Charles III was crowned at Westminster Abbey, the Duke of Sussex was part of the congregation.
As the crown was held above the King’s head, Prince Harry watched intently from the third row.
Upon arriving at the Abbey, the duke appeared relaxed and chatting with his cousins Princess Beatrice and Princess Eugenie.
This is thought to be the first time he has seen his family since he released his controversial memoir, Spare.
According to reports, he will return to the US after the birthday ceremony for his son.
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He was seen smiling at guests as he walked down the nave of the abbey, before chatting with several family members as he entered the Abbey, dressed in a morning suit and wearing medals.
As he took his place beside Jack Brooksbank – husband of Princess Eugenie – and Prince Andrew in the third row, he tapped Princess Beatrice’s husband Edoardo Mapelli Mozzi on the back with a smile.
Princess Anne and the Duke of Kent, Queen Elizabeth II’s first cousin, dressed in Garter robes, sat behind him in the second row.
Along with them were the Prince and Princess of Wales and their children Princess Charlotte and Prince Louis, as well as the King’s brother, Prince Edward, and his wife Sophie.
At the late Queen Elizabeth’s funeral last year, Prince Harry sat in the second row, directly behind the King.
In television footage, the prince watched intently as the archbishop raised St Edward’s Crown above his father’s head.
In the congregation’s homage to the new monarch, Prince Harry was seen saying: “God save King Charles. Long live King Charles. May the King love forever.”
A few hours after landing at London’s Heathrow Airport on Friday morning, the prince reportedly stayed at Frogmore Cottage, the residence he and Meghan were asked to vacate by the King.
The Duke of Sussex has remained in Los Angeles with their children, where their son Prince Archie will celebrate his fourth birthday.
Page Six reported that Prince Harry intended to get back in time for Archie’s birthday.
Prince Harry will attend the ceremony alone, Buckingham Palace confirmed last month.
As members of the Royal Family not working, Prince Harry and his uncle Prince Andrew will not play a formal role in the ceremony.
In spite of serving in the army for a decade, including two tours in Afghanistan, he does not wear robes or military uniforms.
Meghan stays in the United States
The publication of Prince Harry’s memoir has strained relations with other family members.
He has since spoken of feeling “different” from the rest of his family following the book’s vivid description of fall-outs and disagreements with relatives.
As a result of these ongoing, unresolved family tensions, Meghan rejected the invitation.
Last month, it was revealed that the King tried to stop Prince Harry from taking legal action against newspapers for alleged phone hacking.
According to court papers, Prince Harry was “summoned to Buckingham Palace” and told to drop the cases due to the family’s impact.