Prince Harry and members of Princess Diana's family attended a service at St. Paul's Cathedral concurrently, while the monarch and queen hosted a garden celebration.

Without his wife Meghan Markle, 42, and their kids Archie and Lilibet, the 39-year-old Duke of Sussex landed in the UK on Tuesday for the Invictus Games' 10th anniversary thanksgiving service.

Prince Charles, meantime, welcomed guests at Buckingham Palace's inaugural garden party of the year, a few miles away.

Harry's spokesman said that although the King and his son were nearby, the King's hectic schedule prevented them from meeting during Harry's brief visit. But the statement indicated optimism for a later meeting.

The funeral was attended by Diana's siblings Earl Spencer and Lady Jane Fellowes as well as retired army officer Mark Dyer, who mentored Harry and provided him with support when Diana passed away, much like a big brother.

Harry hasn't been back in the UK since February, when he paid the King a quick visit after learning of his illness.