King Charles and the Princess of Wales were both diagnosed with undisclosed forms of cancer earlier this year

As both the King and the Princess of Wales faced cancer diagnoses this year, the close relationship between Charles and his “beloved daughter-in-law” has become increasingly apparent.

Charles and Kate were both diagnosed with undisclosed forms of cancer earlier this year following overlapping stays at a private hospital in London in January.

The King revealed his diagnosis to the nation in early February while Kate followed suit six weeks later following massive amounts of online speculation as she stayed out of the public eye.

While Kate continues to rest, Buckingham Palace announced on Friday evening that the King will be returning to public duties next week for the first time since he began treatment.

Prince Charles and the Duchess of Cambridge at The Order Of The Garter Service in June 2014

As both undergo their respective cancer treatments, the two senior royals have also turned to each other for support.

Charles is said to have driven to Windsor Castle to have lunch with Kate just one day before she announced that she had been diagnosed with the illness.

It is believed that the pair discussed her upcoming announcement, with the King left feeling “very emotional”.

In a short message after the announcement, Buckingham Palace said: “His Majesty is ‘so proud of Catherine for her courage in speaking as she did’.

“Following their time in hospital together, HM has ‘remained in the closest contact with his beloved daughter-in-law throughout the past weeks.’”

Charles is said to have driven to Windsor Castle to have lunch with Kate just one day before she announced that she had been diagnosed with the illness (AP)

A royal source told The Times how the King’s own announcement encouraged his daughter-in-law to follow in his footsteps.

“A factor in their [Kate and William’s] decision to go public would have been the great warmth and affection received by the King as a result of his announcement,” they told the paper.

‘It meant a huge amount to him. In some ways it provided a template.’

In January, they both spent time at The London Clinic, a private hospital in Marylebone, with Charles said to have been seen “toddling” from his hospital bed to spend time with Kate, after she underwent major abdominal surgery.

The 75-year-old monarch was himself being treated for an enlarged prostate, and revealed in February that cancer had been discovered during the course of his treatment.

“They are very close and he thinks of Catherine as his daughter. There is no doubt there is a lot they can share and can use each other for support during their own deeply personal cancer battles,” a source at the time told The Sun.

Kate and Charles have enjoyed a close bond since the princess was introduced into the royal fold.

The two could be seen giggling and laughing together on the red carpet for the 24th James Bond film ‘No Time To Die’ (AP)

In pictures taken at the 2021 premiere of the 24th James Bond film ‘No Time To Die’, the two can be seen giggling and laughing together on the red carpet.

In an interview to mark their engagement, Kate also said Charles had been “very, very welcoming” and “very friendly” when she first met the family.

She admitted being nervous to meet the then-Prince of Wales but added: “It couldn’t have gone easier, really for me.”

Though the pair are both facing similar health challenges, it was announced on Friday that King Charles is set to return to public duties after his treatment had a “positive effect”.

Despite the news, sources said that the King still has cancer and would continue to undergo treatment while managing his summer schedule.

The Buckingham Palace spokesperson said: “His Majesty’s treatment programme will continue, but doctors are sufficiently pleased with the progress made so far that the King is now able to resume a number of public-facing duties.

“Forthcoming engagements will be adapted where necessary to minimise any risks to His Majesty’s continued recovery.”