The royals may be some of the most famous and most privileged people around the world but that doesn't mean they are exempt from difficult periods in their life.
The Princess of Wales bravely revealed her cancer diagnosis in an emotional and incredibly moving video message last Friday, adding: "At this time, I am also thinking of all those whose lives have been affected by cancer. For everyone facing this disease, in whatever form, please do not lose faith or hope. You are not alone."
Like Kate, many royal women from different families across Europe and the world have experienced challenging times and heartbreak of their own.
Some Princesses and Queens have even chosen to speak about those challenges in personal interviews or through their own work, including Crown Princess Victoria of Sweden and Crown Princess Mette-Marit of Norway.
Crown Princess Victoria's battle with anorexia
The Swedish palace confirmed that future queen Crown Princess Victoria was suffering from an eating disorder, following a wave of public concern.
The Crown Princess, then 20, delayed taking up her place at Sweden's Uppsala University to seek treatment in the US.
Ahead of her 40th birthday in 2017, Victoria spoke about her disorder in a two-part programme Crown Princess Victoria, 40 years on Sweden's TV4.
She said: "In the US, I got professional help, which was really important for me. Just learning to put words to feelings and thus, be able to set limits and to not push myself too much, which I found easy. I wanted all the time so much more than I could do, or could be."
In an interview to mark her 21st birthday, she revealed she had turned a corner and thanked the media for allowing her privacy to recover.
She said at the time: "It's not always about external problems. It can also come from within, and it can happen to everyone, not only young girls but also boys."
"I needed time to sort things out and get my balance back again."
Queen Maxima's personal tragedy
The Argentine-born Dutch queen faced a personal tragedy in 2018 with the death of her sister, Inés Zorreguieta, who died at the age of 33 from an apparent suicide.
After taking some time off from royal duties to process her grief, Maxima made a tearful statement during her first engagement after her sister's death, telling reporters: "Today is my first day back at work after a difficult time,” she said. “And actually, I’m happy that I could pay this visit to the Proton Therapy Center in Groningen, because this place means so much to people with cancer."
"People who are sick, yet who hope for a cure,” she added. "My dear, gifted little sister Inés was sick too. She could find no joy, and she could not be cured."
"Our only comfort is that she has now at last found peace. And I would like to say how very grateful we are for the countless letters, messages and tokens of sympathy that we have received. They have really helped us. I’d also like to say thank you for the respect that everyone has shown my family in this very dark period. Thank you, thank you, thank you."
Princess Charlene's health issues
Monaco's Princess Charlene was forced to stay in South Africa for six months in 2021, following an ear-nose-throat (ENT) infection, and underwent several surgeries.
During her recovery period, the royal missed her tenth wedding anniversary with Prince Albert, with Charlene releasing a statement, which read: "This year will be the first time that I’m not with my husband on our anniversary in July, which is difficult, and it saddens me.
"However, Albert and I had no choice but to follow the medical team's instructions even though it is extremely difficult. He has been the most incredible support to me.
"My daily conversations with Albert and my children help immensely to keep my spirits up, but I miss being with them. It was special to have my family visit me in South Africa, and it was truly wonderful seeing them. I can't wait to be reunited with them."
Speculation surrounding Albert and Charlene's marriage at the time of her health crisis mounted, with the prince telling PEOPLE magazine at the time: "Because I know there are rumours out there, let me say: This is not COVID. And it's not cancer-related. It's not a personal relationship issue. And if you want to discuss another speculation, it isn't related to plastic surgery or facial work at all."
Albert reiterated: "These are not problems within our relationship; not with the relationship between a husband and wife. It's of a different nature."
Charlene was reunited with her family in Monaco in November 2021, and then spent time in a treatment facility outside of the principality.
In May 2022, she finally returned to the public eye, stepping out at the ABB FIA Formula E World Championship in Monaco.
Crown Princess Mette-Marit's lung disease diagnosis
In October 2018, the Norwegian palace confirmed that Crown Princess Mette-Marit had been diagnosed with chronic pulmonary fibrosis, a lung disease that occurs when lung tissue becomes damaged and scarred.
In a statement at the time, Mette-Marit, who is now 50, shared: "For a number of years, I have had health challenges on a regular basis, and now we know more about what these are. Although such a diagnosis will limit my life at times, I'm glad that the disease has been discovered so early. My goal is still to work and participate in the official programme as much as possible."
Due to her health, Mette-Marit has had to restrict her royal duties. In 2019, she told TV network NRK: "I am exhausted faster than before, so today I have to take more care of myself than I did before."
Queen Letizia's personal tragedy
Letizia, who was then princess, was rocked by the sudden death of her younger sister, Erika Ortiz, in 2007.
The Spanish royal was pregnant with her second child, Infanta Sofia, when Erika died by suicide at the age of 31.
She was visibly emotional and tearful at Erika's funeral but paused for a moment following the service in Madrid to acknowledge the support shown by members of the public.
"Thank you to everyone who has shown sympathy following the death of my little sister," she said.
Since becoming queen in 2013, Letizia has raised awareness for mental health and even rapped on stage to mark World Mental Health Day last October.
She opened her speech by reciting lyrics by Madrid-born rapper, El Chojin, before adding: "If today or tomorrow even one newspaper writes, 'The Queen Raps for the Mental Health Day it will bring attention to the cause."
Empress Masako's stress-related illness
In 2004, it was confirmed by the Imperial Household Agency that the Princess Masako had been diagnosed as suffering from "adjustment disorder" and was reported to be seeking treatment.
She withdrew from public life for over a decade but has gradually returned to her duties.
Ahead of her husband Emperor Naruhito's enthronement in 2019, Masako said of her role as Empress: "Giving thought to the days ahead, I sometimes feel insecure about the extent to which I will be able to be of service to people. But I will strive to do my best so that I can contribute to their happiness."
If you have been affected by this story and wish to seek help, Samaritans (116 123) operates a 24-hour service available every day of the year.