Prince William has admitted this “has been the hardest year of my life” as he opens up on his father and wife’s cancer diagnosis for the first time.

In January both the King and the Princess of Wales underwent operations and were subsequently diagnosed with cancer.

While Kate has completed her course of chemotherapy, Charles continues to receive weekly treatment – but continues to busy himself with official duties and public engagements.

Asked how the past 11 months have been for him, William said: “Honestly? It’s been dreadful. It’s probably been the hardest year in my life. So, trying to get through everything else and keep everything on track has been really difficult.”

Speaking in an interview with the UK print media travelling with the Prince on his four-day trip to Cape Town for his Earthshot prize, William said he was incredibly proud of Charles and Kate for how they’ve responded to their diagnosis.

“I’m so proud of my wife, I’m proud of my father, for handling the things that they have done,” he said. “But from a personal family point of view, it’s been, yeah, it’s been brutal.”

William has not publicly spoken about how his wife or his father’s cancer diagnosis has affected him, though in Kate’s most recent statement, she spoke of how hard the period had been for the family.

“The last nine months have been incredibly tough for us as a family,” she said. “Life as you know it can change in an instant and we have had to find a way to navigate the stormy waters and road unknown.”

The princess added: “This time has above all reminded William and me to reflect and be grateful for the simple yet important things in life, which so many of us often take for granted,” she said. “Of simply loving and being loved.”

Some commentators have interpreted William’s new beard as a sign that he is feeling more relaxed now that his wife’s cancer treatment has ended, but this is something he refuted.

He said: “It’s interesting you say that, cause I couldn’t be less relaxed this year, so it’s very interesting you’re all seeing that.

“But it’s more a case of just crack on and you’ve got to keep going. I enjoy my work and I enjoy pacing myself and keeping sure that I have got time for my family too.”

William revealed that his daughter cried when she first saw his beard, prompting him to go back to clean shaven.

Asked if the family like his new look, he said: “Well Charlotte didn’t like it the first time. I got floods of tears, so I had to shave it off.

“And then I grew it back. I thought, hang on a second and I convinced her it was going to be okay.”

William debuted the beard in a video message congratulating Team GB’s athletes at the Paris 2024 Olympics in August but later appeared clean-shaven at church two weeks later.

But as he commenced his autumn schedule of engagements the beard had returned.

In January Kate spent 13 days in hospital following abdominal surgery and two months later she bravely revealed she had been diagnosed with cancer and started a course of chemotherapy.

The princess stepped out for just two public engagements during this time, for Trooping the Colour and the Men’s Wimbledon Singles Final, before revealing in September she had completed her treatment and was “looking forward to being back at work”.

The King was in hospital at the same time as his beloved daughter, for a procedure on an enlarged prostate, during which time his cancer – not affecting his prostate – was discovered.

His diagnosis was announced on February 6 and he postponed all public-facing engagements for several months before easing himself back into royal duties.

Charles continues to undergo treatment, though his recent trip to Australia and Samoa with the Queen has been described as the “perfect tonic” for the 75-year-old.

Elsewhere in the interview, William said last night’s Earthshot Prize Awards Ceremony in the South African capital left him feeling emotional but he is determined to increase the visibility, impact and scale of the environmental award over the next six years.

He called on businesses to “hurry up and be courageous”, telling them: “Invest faster because we just don’t have that time.”

William has been the Prince of Wales for over two years now and asked how he’s finding the new role, he feels conflicted.

“It’s a tricky one,” he said. “Do I like more responsibility? No.

“Do I like the freedom that I can build something like Earthshot then yes.

“And that’s the future for me. It’s very important with my role and my platform, that I’m doing something for good. That I’m helping people’s lives and I’m doing something that is genuinely meaningful.”