For the royal family, Catherine has been a dream princess. After the turbulent years of Diana and Sarah Ferguson, the royals were delighted when William became romantically involved with the nice, middle-class girl from the home counties when the pair were studying at St Andrews University.

Since then, there has been a fairytale wedding, three healthy children, and a princess to be proud of: calm, cheerful and devoted to her job as wife and mother to the future king and his siblings.

After her cancer diagnosis, made public on Friday, William, the children, her parents and her in-laws will be coming to terms with a serious health crisis and an uncertain future in the glare of global media coverage. No wonder she wanted privacy.

Catherine and William met in 2001 when she took part in a charity student fashion show that the prince attended. The following year, they shared a student flat with two others. At this point they were just friends.

That changed over the following months and years, and by the time they graduated in 2005 they were a couple. But in 2007, they took a few months out from their relationship. Catherine later said: “I think I at the time wasn’t very happy about it, but actually it made me a stronger person … You find out things about yourself that maybe you hadn’t realised … I really valued that time for me as well although I didn’t think it at the time, looking back on it.”

The break didn’t last. In March 2008, the couple were photographed on the ski slopes in Klosters, and in October 2010 William proposed while on a trip to Kenya. “I just decided it was the right time really,” he said later. “We’d been talking about marriage or a while, so it wasn’t a massively big surprise.”

Marriage was an enormous commitment, and not just to one another. For Catherine, it meant her life would be lived in the public eye, under constant scrutiny and immense pressure to deliver for the royal family. She knew how challenging it would be.

William and Kate married on 29 April 2011 in a ceremony at Westminster Abbey that was broadcast around the world. Two years later, after a pregnancy blighted by severe morning sickness, she gave birth to her first son, George. Charlotte followed in 2015 and Louis in 2018.

The Princess of Wales has issued frequent updates about her family life. During the Covid pandemic, she spoke in a BBC interview about the challenges of parenting through lockdown. “It’s been ups and downs, like a lot of families self-isolating,” she said.

On their 10th wedding anniversary, the couple posted a video of themselves and their children walking through sand dunes in Norfolk, thanking people for their well wishes. Other photos and messages were posted online at Christmas, Mother’s Day and anniversaries.

It has not been all smooth sailing. Catherine and the Duchess of Sussex were said to have a fractious relationship, perhaps contributing to the growing distance between William and Harry. She and her father-in-law – then Prince Charles, now the king – were named in the Dutch version of a book as the members of the royal family who had allegedly expressed concerns about how dark the skin of Harry and Meghan’s unborn child might be.

But public affection for the Princess of Wales has been remarkable. She has been widely praised for her sunny demeanour, charity work, fashion sense, parenting skills and informality.

When it was announced in January that she had had planned abdominal surgery, speculation about her health inevitably took off. The surgery had been successful, said Kensington Palace, and she would spend some weeks recovering at home.

“The Princess of Wales appreciates the interest this statement will generate,” it said. “She hopes the public will understand … her wish that her personal medical information remains private.”

After weeks of hysterical speculation and wild conspiracy theories, that period of privacy has come to an end. It had been “an incredibly tough couple of months” for her and her family, she said in her video statement released on Friday. No doubt, it will continue to be tough for some time to come, but public sympathy will be unbounded.