Princess Kate and King Charles may be facing simultaneous cancer battles, but the two have shared many lighthearted moments over the years

Prince William, Kate Middleton and King Charles. PHOTO:

DARREN STAPLES – POOL/GETTY

Kate Middleton and King Charles’ bond runs deep.

Since her April 2011 wedding to Prince William, Princess Kate has fulfilled her royal duties wherever they take her, including several outings with the current monarch. More recently, however, their bond has taken an unexpected turn as they’re both dealing with cancer diagnoses, marking the first time in history two senior royals are navigating the disease at the same time.

“They are in this together, Kate and the King,” royal biographer Sally Bedell Smith told PEOPLE of the monarch and Kate’s shared experience.

Take a look back at some of Kate Middleton and King Charles’ best photos together.

01of 10Longstanding BondKate Middleton and King Charles.

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After Kate’s diagnosis was made public to the world on March 22, royal biographer Sally Bedell Smith told PEOPLE that King Charles “has always had a very good bond with her.”

“I don’t think it is presumptuous to say that she is like the daughter he never had,” she continued. “He shares with William an impulse to protect her. They are in this together, Kate and the King.”

Their bond can be seen on this early visit — not long after Kate wed Prince William in 2011 when the two paid a visit to The Prince’s Foundation for Children and The Arts at Dulwich Picture Gallery in London to participate in crafts with some of the children.

02of 10Side by SideKate Middleton and King Charles.

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Coincidence? The two even wore similar hues during the visit, which took place on March 15, 2012, a month shy of Kate’s first wedding anniversary.

03of 10Artsy OutingKate Middleton and King Charles.

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In 2022, the Princess of Wales can be seen delighting her father-in-law in conversation as they visit the Clore Drawing Studio to speak to students.

04of 10Special GreetingPrince William, Kate Middleton and King Charles.

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The day before the Princess of Wales shared her diagnosis, the King and his daughter-in-law, who are seen here in 2017, shared a private lunch at Windsor Castle.

Buckingham Palace said the monarch was “so proud of Catherine for her courage in speaking as she did” in her announcement that was shared widely on March 22.

05of 10Family PortraitQueen Camilla, King Charles, Prince William and Kate Middleton.

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Being the four senior-most members of the royal family, Queen Camilla, King Charles, Prince William and Princess Kate often attend some of the royal family’s biggest events together. In this glamorous portrait, the four were dressed to the nines at The Diplomatic Reception in the 1844 Room at Buckingham Palace in December 2023.

06of 10Having a ChatKing Charles, Kate Middleton and Prince William.

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Kate, the then-Prince of Wales and Prince William were clearly engaged in a lively chat during a visit to Dumfries House in Scotland in 2013.

07of 10Cheek to CheekKing Charles and Kate Middleton.

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The future monarch greeted his daughter-in-law sweetly with a kiss on the cheek at the premiere of No Time To Die at the Royal Albert Hall in 2021.

08of 10Something to Laugh AboutQueen Camilla, Prince William, Kate Middleton and King Charles.

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Charles sure seems to bring a smile to his daughter-in-law’s face during an outing with William and Camilla to the Defence Medical Rehabilitation Centre in Loughborough in February 2020.

09of 10Hats OnKing Charles and Kate Middleton.

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The two appeared in good spirits while sporting fabulous head pieces at the Order of the Garter Service at St George’s Chapel in June 2022 in Windsor.

10of 10Big SmilesKing Charles, Kate Middleton and Prince William.

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A wider shot from the day shows Charles flashing a wide grin as he shares a moment with William and Kate, who looked lovely in bright blue.