On Tuesday morning, the princess had spoken to cancer patients at the Royal Marsden with the empathy of her own first-hand experiences, in her most significant solo royal engagement since her treatment ended.

Catherine told a woman who was having chemotherapy: “It’s really tough… It’s such a shock… Everyone said to me, ‘please keep a positive mindset, it makes such a difference’.”

Arriving as a visitor now rather than as a patient, the princess sympathised with those undergoing treatment – and described how she was still feeling the long-term effects.

“You think the treatment has finished and you can crack on and get back to normal, but that’s still a real challenge,” she said.

“The words totally disappear. And understanding that as a patient – yes, there are side effects around treatment, but actually there are more long-term side effects.”

Asked how she was feeling, Catherine said she was doing well, but added: “Sometimes from the outside we all think you’ve finished treatment and you go back to things. But it’s hard to get back to normal.”