Prince Harry reunited with Princess Diana's family to celebrate the Invictus Games. The royal family didn't attend.

• Prince Harry is in the UK to celebrate 10 years of the Invictus Games.
• He attended a Service of Thanksgiving on Wednesday with several of Princess Diana's relatives. 
• King Charles III skipped the service for a garden party, and Prince William didn't attend either.

The royal family was noticeably absent from a ceremony celebrating the Invictus Games.

The Invictus Games, a worldwide sporting competition for injured veterans, marked 10 years since its creation on Wednesday.

Prince Harry serves as the founding patron of the organization, creating it after working directly with injured soldiers during his time in the military.

The organization has seen steady growth in recent years, increasing its annual income from about $1.2 million to $2.5 million from 2018 to 2022, according to the Charity Commission for England and Wales.

As part of the anniversary celebrations, The Invictus Games Foundation hosted a Service of Thanksgiving at St Paul's Cathedral in London.

Harry traveled to the UK to attend the ceremony and other events marking the anniversary.

The royal family skipped the ceremony

Harry was the only member of the monarchy to attend the Service of Thanksgiving, though royals have supported him at Invictus Games events in years past.

King Charles III, who returned to public duty at the end of April, was in London during the event, hosting an annual garden party at Buckingham Palace with Queen Camilla on Wednesday instead of attending the service.

Though his royal family wasn't at the event, Harry reunited with Diana's siblings, Earl Charles Spencer and Lady Jane Fellowes, at the Service of Thanksgiving.

The Daily Mail published video footage of Harry hugging his Spencer relatives inside the event.

Harry reportedly won't see King Charles during his visit to the UK

Harry's relationship with the royal family has been strained since he and Meghan Markle stepped back as senior royals in January 2020.

However, Harry has supported Charles over the past year, attending his coronation in May 2023 and visiting him amid his cancer diagnosis. He met with the king and Queen Camilla for about 45 minutes shortly after the monarch announced his diagnosis to the public, the BBC reported.

In an interview with Good Morning America following the visit, Harry said he was "grateful" he could see the king after his diagnosis, adding that he planned to "stop in and see my family as much as I can."

However, a spokesperson for Harry and Meghan said in a statement to Reuters that the Duke of Sussex would not be able to see the king during his latest visit to the UK because of the monarch's schedule.

"In response to the many inquiries and continued speculation on whether or not the duke will meet with his father while in the UK this week, it unfortunately will not be possible due to His Majesty's full programme," the statement said, according to Reuters. "The duke of course is understanding of his father's diary of commitments and various other priorities and hopes to see him soon."

Buckingham Palace and the Sussex team did not respond to a request for comment from BI.

Prince William did not attend the Service of Thanksgiving either, nor did he and Harry see each other during the Duke of Sussex's visit in February.

The brothers have reportedly had a rift for years, particularly since Harry discussed their relationship in his Netflix series "Harry & Meghan" in December 2022 and his memoir "Spare" in January 2023.

Harry and Meghan released a statement to the BBC following Kate Middleton's announcement that she was undergoing "preventative chemotherapy," saying, "We wish health and healing for Kate and the family, and hope they are able to do so privately and in peace."

The duke and duchess have not publicly connected with the Prince and Princess of Wales since Kate's diagnosis.