Kate Middleton and King Charles' Cancer Battles 'Drew' Them 'Closer': Princess 'Was the One Comforting' the King 'at Times'

Kate Middleton brought out King Charles’ softer side as both royals battled health issues.

“Charles used to seem like a very standoffish guy — and he didn’t do much to make himself more likable or accessible to the public,” an insider said of the father-of-two.

“Because she loves spending time with him, Kate’s been giving Charles a little nudge recently to let his guard down and provide the world with a glimpse of the Charles she admires. He’s listened and told those closest to him that, even at his age, he’s still learning lessons from Kate.”

The mother-of-three's touch has been evident recently, as the King showed a rare emotional side during his trip to Australia and Samoa in October.

“I shall always remain devoted to this part of the world and hope that I survive long enough to come back again and see you,” they shared. “We shall take away with us, I promise you, very special memories of our time here.”

The source added that Charles’ behavior may be shocking to the public, but those close to him know it as his real personality.

“The truth is, behind the scenes, Charles was always pretty down-to-earth,” the insider spilled. “For example, he just loves being in nature, which is something he and Kate have in common. He also loves to cook and swim, and he adores his grandchildren.”

Charles and Kate’s cancer battles have also strengthened their relationship.

“Fighting cancer at the same time drew Kate and Charles closer,” the source shared. “Kate was the one comforting Charles at times, but he also really took his royal hat off to just be a supportive father-in-law.”

“While the world may have seen this stiff-upper-lip royal, Kate knows Charles as the guy with a silly sense of humor,” they continued.

“Around her and the family, Charles is easygoing, eager to listen to stories, and a funny grandfather. So she’s encouraged him to use those qualities to bond with people. Now he’s happy he took her advice,” the insider added.

As OK! previously reported, the new chapters of Charles’ biography Charles III. New King. New Court. The Inside Story revealed his reaction to his cancer diagnosis.

"Cancer is a very scary word if you're a king or anyone else. It's a big shock. But he is a great one for taking things on the chin," a source told royal author and historian Robert Hardman. "'How are we going to get on with this?' He was very clear that he would carry on doing all of the constitutional stuff in exactly the way that he did before.”

Life & Style reported on how Kate has influenced Charles.