Prince Harry marked the 10th anniversary of his Invictus Games at St Paul’s Cathedral on Wednesday with a speech honoring the legacy of the event he founded in 2014.

While neither his father King Charles nor his brother Prince William were in attendance, Harry beamed as he entered the cathedral where his parents were married and greeted the waiting press.

When asked whether he was happy to be back in the UK, Harry appeared to chuckle but despite smiling for the cameras, he is said to be deeply disappointed that he will not get to see his father during his three-day visit home.

Despite being invited, none of the royal family attended Wednesday’s milestone anniversary service. On Tuesday, a spokesman for Harry confirmed that he would not be meeting with his father even though Charles is in London. According to the spokesperson, there was no time in the king’s busy schedule for Harry, and added that the Duke of Sussex “is understanding of his father’s diary of commitments…and hopes to see him soon.”

While Harry was attending the service at St Paul’s Cathedral, Charles carried out a busy day of engagements, including his weekly audience with Prime Minister Rishi Sunak and attending a garden party at Buckingham Palace. He received a show of support from family members including Anne, Princess Royal, Prince Edward, Duke of Edinburgh and Sophie, Duchess of Edinburgh and Birgitte, Duchess of Gloucester, and Prince Richard, Duke of Gloucester.

King Charles, who is undergoing cancer treatment, is carrying out engagements under the guidance of his medical team and has been urged not to take on too much.

However, a family friend said that Harry would be hurt by his father not making time for him. “It feels very much like a snub. Harry is rarely in Britain and when he does come over he obviously wants to see his father. He doesn’t know when he will next be here and he is very worried about his papa and desperately wanted to see him.”

It is understood the two men have spoken on the phone since Harry has been back in the UK.

When the King was diagnosed with cancer, he phoned his son personally, prompting Harry to fly to Britain immediately. Charles made adjustments to his schedule so that he could see his son before traveling to Sandringham to recuperate. Nevertheless, Charles, who had an audience at Buckingham Palace on Tuesday and will visit the Royal School of Military Engineering in Surrey on Thursday, has no free time to see Harry during his visit.

“The king has been keen to get on with his diary after the setback earlier this year and there is no time to see Harry,” says a source. “The king would have loved to see his son, but on this occasion, it couldn’t be worked out.”

Harry, who is in the UK for three days before heading to Nigeria where he and his wife Meghan Markle are carrying out a tour at the invitation of the Nigerian government, will also not be seeing his brother or sister-in-law, Kate Middleton. William is traveling to the Isles of Scilly over the next two days, while Kate is in Windsor undergoing chemotherapy.

Harry is reportedly staying in a Windsor hotel, but despite being just a stone’s throw from William and Kate’s family home, there will be no meeting.