Princess Kate has been the popular face of the royal family. What now?

Though she is formally known as Catherine, the Princess of Wales, for millions worldwide she will always just be Kate Middleton: The English commoner who married a prince and whose elegant but accessible image has cemented her as Britain’s favorite royal.

That’s why the saga around her unexplained surgery and subsequent altered family photo has been so damaging for this ancient institution, commentators say. Particularly coming at a time when the royals find themselves short of headline acts, following the death of Queen Elizabeth II, the recent cancer diagnosis of King Charles III, and with Prince Harry and his wife, Meghan, living in California.

Until her leave of absence, Kate had been picking up the slack, both a reliable royal foot soldier and someone able to bring star power to even the most mundane ribbon-cutting event. And Kate and her husband, William, the Prince of Wales, had largely navigated their desire for privacy with their growing public duties once he became heir to the throne.

“William and Kate are individually extremely popular — they are the two most popular members of the royal family,” NBC News royal commentator Daisy McAndrew said. “Kate, even more than William, has always had this can-do-no-wrong reputation, so for her to be criticized will be tough for the royal family to swallow.”

Though Charles is king and William is his heir, it is Kate — the future queen — who regularly polls as the nation’s favorite member of this birthright clan.

Once again this week, a survey from pollster Ipsos had Kate as the most popular royal, with 38% of the 1,085 respondents in Britain ranking her as their No.1 ahead of William. Though released Wednesday, it was conducted prior to the British Mother’s Day photo scandal .

Of course, that popularity is not universal, particularly since the very public falling out between William and Kate, and Harry and Meghan. Almost every royal storyline is now framed by the media as part of the wider struggle between cheerleaders for Team Wales and those for Team Sussex.

The latter have claimed that race has been a factor in Meghan’s treatment by parts of British media, which has at times seemed harsher than the coverage given to Kate. One tabloid columnist referred to Meghan’s “exotic” DNA and a Daily Mail headline described her Los Angeles roots as “(almost) straight outta Compton.” 

The same newspaper ran photos of a pregnant Meghan cradling her pregnancy bump under the headline: “Why can’t Meghan Markle keep her hands off her bump?” Months earlier, it had described a pregnant Kate as “tenderly” cradling her bump.

Even this week, while British newspapers have covered the saga at length, much of the commentary has been gentle.

“GIVE KATE A BREAK,”  the right-wing Daily Mail, the country’s top-selling newspaper, thundered on its front page Thursday. The Sun, another popular British tabloid, managed to make the Sussexes the focus of the story with, “MEGHAN AND HARRY ENTER KATE PIC ROW.”

“She is a source of fascination,” royal commentator Tim Ewart told NBC News on Thursday. “Bear in mind that the public and the media do not have the intense interest in the king” — fifth-most popular in the Ipsos poll — “that they do in the princess of Wales, Kate.”

Kate, 42, grew up in Berkshire, an affluent county to the west of London, raised by entrepreneur parents. She went to Marlborough College, an exclusive private school whose fees today are as much as $60,000 a year. She then studied art history at the University of St. Andrews in Scotland, which has one of the lowest percentages of state-educated students of any university in Britain.

It was here that she met William in 2001, their relationship coming to public attention when they were photographed together while skiing in Switzerland. They married in 2011 despite briefly splitting in 2007.

It has not always been a smooth ride with the press. Her lawyers asked photographers to leave her alone in 2005, as she was learning to navigate post-grad working life while in the glare of being a royal girlfriend. In 2012, the couple sued a French magazine for publishing topless pictures of her, taken while she was vacationing at a villa in the south of the country. 

But those were blips for a couple who have always been seen as more willing to play the game than Harry and Meghan: rarely voicing their opinions, and seeking to control the press and public narrative rather than lashing out against it so openly.

That is, until now, with the altered photo — and the fact that she was not wearing her wedding ring in it — only adding fuel to a fire of conspiracy theories and speculation about her health and personal life that the royals are struggling to put out. It has also risked tarnishing the halo, in the eyes of many, of someone whose almost unblemished public relations record was perhaps only rivaled by the late queen herself.

While Kate may share the inoffensive persona that partly explained the queen’s popularity, it may be Elizabeth’s absence and the goodwill buffer she provided that have made the critique of the future queen feel more stark, McAndrew said.

“People knew that when we did go into a post-Queen Elizabeth era, the scrutiny would be more intense. That was something that the royal family knew was coming and knew that they had to prepare for,” she said. “And I think that probably is what we’re seeing now.”