The tennis fan and patron of the All England Lawn Tennis and Croquet Club in Wimbledon, was wearing a bright purple dress as she strode into the venue with her daughter, Princess Charlotte, ahead of the match between Carlos Alcaraz and Novak Djokovic.

Arriving at Centre Court’s royal box to take her seat, Catherine waved to spectators, some holding Union Jack flags, who gave her a standing ovation.

The 42-year old Princess of Wales, wife of heir to the throne Prince William, underwent major abdominal surgery in January which revealed the presence of cancer. She has been undergoing treatment since then.

She made her return to public duties in June at the ‘Trooping the Colour’, the annual military parade to mark the official birthday of King Charles, and said she hoped to attend other events over the summer.

“I am making good progress, but as anyone going through chemotherapy will know, there are good days and bad days,” she said in a personal written message ahead of that appearance.

“My treatment is ongoing and will be for a few more months,” said the princess.

Her office, Kensington Palace, has declined to give specific details about the type of cancer or her medical condition, other than to say the treatment had begun in February.

Charles, 75, has also been undergoing treatment for cancer. He returned to public duties in April, and has remained busy, although his daily commitments are being limited to minimise risks to his recovery.