Prince William, Kate Middleton's wedding anniversary 'bittersweet' as they face 'greatest challenge': expert

The Prince and Princess of Wales are celebrating their 13th wedding anniversary, and the occasion is "bittersweet," one royal expert told Fox News Digital.

Prince William and Kate Middleton married on April 29, 2011, at London’s Westminster Abbey. To commemorate the occasion, the couple shared a previously unseen photo from their special day on social media, with the caption, ‘13 years ago today!’ 

Westminster Abbey also shared a heartfelt video from the celebration, showing the newly married royals leaving the church hand in hand.

"This is obviously the most bittersweet anniversary William and Kate have ever experienced," Christopher Andersen, author of "The King," told Fox News Digital. "Their marriage is stronger than ever, they have three beautiful children – and now they are facing the greatest challenge of their married lives."

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In a video shared in March, Middleton revealed that she is battling a form of cancer after having abdominal surgery for undisclosed reasons. The 42-year-old said she has been undergoing preventative chemotherapy treatment.

On Friday, Buckingham Palace confirmed that the royal's father-in-law, King Charles III, will resume his public duties. In February, the palace announced that the 75-year-old had been diagnosed with a form of cancer and is undergoing treatment.

Andersen said that despite the ongoing health battles, the Prince and Princess of Wales have put on a united front.

"It’s hard to think of any marriage stronger than theirs or built on a more solid foundation," he shared. "William and Kate are certainly more equipped emotionally and in every other way to handle whatever life throws at them – and with the dual diagnoses of Kate and the king, life has thrown them a lot."

Royal expert Ian Pelham Turner told Fox News Digital that the couple is optimistic about Middleton’s recovery.

"The couple are working behind the scenes," Pelham Turner claimed. "I have been told by a source who is in regular, almost daily contact with the couple that they are putting in day's work, especially William – and Kate when she is able to."

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"The abdominal surgery, apart from being very painful, was emotionally draining for Kate," he said. "The couple had to come to terms with all of this even before the cancer announcement. William has stepped up to the plate, ensuring his family and his family are confidently moving forward."

According to Pelham Turner, the couple have prioritized protecting their children from the glaring media spotlight. The princess has maintained a low profile during her recovery.

Middleton's absence from the public eye – and little information about what prompted her surgery – initially triggered speculation and gossip about her health. Distrust of the monarchy only intensified after the princess admitted that she edited an official family photo, one that was supposed to reassure the public that she was doing well. Palace officials struggled to regain control of the narrative as conjecture and conspiracy theories persisted.

In her announcement, Middleton said it had been thought that her condition was non-cancerous until post-surgery tests revealed the diagnosis.

"This, of course, came as a huge shock, and William and I have been doing everything we can to process and manage this privately for the sake of our young family," she said.

Pelham Turner noted that Middleton had been determined to give their children normalcy behind palace doors.

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"Together, [William and Kate] are working extremely hard to protect their children from any worries they may have and keep normality in their daily lives," Pelham Turner explained. "For Prince Louis’ sixth birthday, Kate kept her tradition going by baking midnight cakes for the young man. It’s a tradition she has done for many years."

Former royal butler Grant Harrold told Spin Genie that William, 41, plans to make the couple's anniversary a special day.

"With everything going on with Kate, that won't be a public thing, that's going to be very private," he told the outlet. "Behind closed doors, I'm sure William will work to make sure she's spoiled."

"It's possible William might cook. He's quite a good cook, so it's possible he might do a little meal or something," Harrold explained. "Again, it's just going to be a private affair between the two of them. Once again, there'll still be an exchange of gifts. I have no doubt they will give each other a gift, and I've no doubt they will exchange cards."

"I've no doubt that there'll be a special meal for them, whether it's a meal where they invite friends and family, or just them," he shared. "Again, well-wishers will pass on their love with cards."

Kinsey Schofield, host of the To Di For Daily podcast, told Fox News Digital that William has long pledged to be by his wife’s side, especially during tough times.

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"I think it’s worth noting that before Prince William asked Kate Middleton to marry him, he promised Michael and Carole Middleton that he would protect their daughter to the best of his ability," said Schofield. "We have seen that throughout 2024."

"He has been fiercely protective of his family while maintaining stoicism and marching on with his royal duties," Schofield shared. "So much fear must have been associated with taking on the role of future Queen Consort. Especially growing up in a world where you witnessed the death of Princess Diana and the aftermath. That is why I've always believed that William and Kate's relationship was driven by genuine love for one another."

"They both have made significant sacrifices for the crown, yet they always prioritize their family - that is their core," Schofield continued. "Their little family is at the heart of everything they do. . . . This is likely to be an emotional anniversary. The Prince and Princess of Wales will most certainly watch clips of their wedding day in newspapers and on the television, and they might admire what an incredible day it was for both them and the country.

"The Wales family is a beautiful portrait of the future, happiness and hope. A clean slate. Mostly scandal free. Britain looks forward to their reign, but not anytime soon. I think they recognize how important Prince William's children are to him and want to allow him the freedom to father them the way he aspires to."

British broadcaster and photographer Helena Chard told Fox News Digital that the Prince and Princess of Wales are "each other’s cheerleaders," which has been the secret behind their 13-year marriage.

"There is no trying to take center stage," Chard explained. "They enjoy the simple things in life, like enjoying the great outdoors with their family. They share similar passions and goals. Their competitive sporting nature keeps their flame alight. Their personalities are compatible."

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"Prince William can be stubborn on occasion and Princess Kate is the peacekeeper," Chard shared. "She is super at diffusing any awkward situations, especially when it comes to her husband and father-in-law, the king. The glamorous couple are conscientious, engaging and relatable people. They are held in high esteem internationally. They are a credit to our royal family and are super important for the future of the monarchy. In fact, they are the face of our monarchy."

Andersen said that following the couple’s special day, we can expect to see William taking on more royal duties in support of his family – and more importantly, his wife.

"Kate is not an emotionless, robotic Stepford Wife as some have accused her of being," he said. "There is an awful lot going on behind that dazzling smile. . . . In that sense, she has always been somewhat guarded. But now there is a bit of a crack in the royal mask, and we all saw it when Kate delivered the heart-stopping news of her cancer diagnosis."

"Of course, Kate has her own family, particularly her mother, Carole Middleton, as a kind of emotional backstop," Andersen noted. "But William, beyond the fact that he has to really step up to support his ailing father the king, must be her main pillar of support. He has to be the one who really holds it all together for the sake of their children."

The Associated Press contributed to this report.