During his speech, William said: “It is my great honour to be with you today, representing my father, His Majesty The King, to mark this significant milestone in your lives and careers.

“I am delighted to see so many family and friends here – I know their love and support will have been instrumental in getting you to this point.”

The late Princess Diana’s siblings were present at Prince Harry’s 10th anniversary of the Invictus Games ceremony back in May.

Earl Spencer and Lady Jane Fellowes walked in side-by-side to St Paul’s before chatting to their nephew, who now resides in the US with his young family. Harry appeared delighted that his aunt and uncle had made an appearance, with the 39-year-old pictured giving them both a hug upon their arrival.

Speaking of the Spencer family, a source has claimed that they could be key in the reconciliation between Harry and William following Sir Robert Fellowes’ memorial service.

A source told the Daily Express: “There was a wake afterwards and Harry had been in the UK since Tuesday spending time with his late mother’s side of the family. Everyone is hoping that there might be some kind of intervention from Jane or Charles [Spencer] which will hopefully bring them back together. It will take some time but it is looking like a possibility.”