Prince William felt ‘inner pride’ to see Princess Kate back at his side for Trooping the Colour, an expert says.

Princess Kate and Prince William’s romantic moment on the balcony of Buckingham Palace has given royal fans a touching insight into their relationship. The Prince and Princess of Wales united for the palace appearance which marks the end of Trooping the Colour.

A special moment was caught on camera when William looks into the eyes of his wife, who made her triumphant return to official royal duties with an outing on Saturday (June 15) which sent royal fans into a frenzy.

Body language expert Judi James told MailOnline William’s eye-crinkling and the puckered muscles around his lips reveal his inner pride and “possible relief” to have Kate standing beside him again.

She said: “Kate, who had relaxed visibly by this stage, pinged back a wide, dimpled and very loving smile.”

Ms James told the same publication Kate’s return to the royal stage was a masterclass in royalty, adding that Kate had learnt from the late Queen by combining stoicism and calm with “not one drop of self-pity or drama”.

After months of chemotherapy, which is still ongoing, the princess joined a highlight of the royal calendar, but still kept a watchful eye on her children, Prince George, Princess Charlotte and Prince Louis, who together stole the show.

Her appearance had been in doubt after she missed the final Trooping rehearsal last weekend, but the spectacle of military pomp and pageantry became a symbolic statement by the monarchy after a period of uncertainty, with King Charles also undergoing treatment for cancer.

Kate and fellow members of the Royal Family were cheered when they were spotted in The Mall on their way to Trooping at Horse Guards Parade.

There were cheers again when the Royal Family stepped out onto the balcony of Buckingham Palace for the RAF flypast.

Kate said in a statement on Friday (June 14) she was making “good progress” with her treatment, but candidly confessed she has “good days and bad days”. Although she has been working from home, Kate said: “I am not out of the woods yet”.

Support from the public has made a deep impression on the princess, who said she had been “blown away” by “kind messages” which had made a “world of difference” to both her and William, helping the couple “through some of the harder times”.

In a departure from last year, Kate did not join senior family members on a dais at Trooping, but watched the ceremonial proceedings from the Duke of Wellington’s former office along with her children.

Kate stunned in a Jenny Packham dress, a hat by Philip Treacy and the Irish Guards Regimental Brooch, as she is the regiment’s Colonel.

Royal fan, James Evans, 24, said Kate looked “very well and radiant as ever”. He added: “I think (her presence) sends a message – one, that she is in recovery and, two, that I think a lot of cancer survivors can feel, sort of, sympathy with that and it’s raised so much awareness about cancer as well – which is fantastic.”

Dame Laura Lee, Chief Executive of cancer support charity Maggie’s, said seeing the Princess of Wales was “just lovely”. She added: “As she said herself, today was a good day. By highlighting that there are good days and bad days, the princess is helping to draw attention and normalise the reality of living with cancer.”