Just as the Princess of Wales’ decision to bring only daughter Princess Charlotte to Wimbledon with her this past Sunday was a significant one, so was Kate’s decision to have her younger sister, Pippa Middleton Matthews, by her side, as well.
“They were already genuinely best friends, but this grueling year has seen them grow even closer,” a source told The Daily Express. “Pippa has been something of an angel and backbone for Catherine. She’s there at the drop of a hat, helping to pick up the slack on physical tasks when needed. But it’s the emotional support she provides that is invaluable to Catherine.”
The sisters’ “unbreakable” bond draws comparison to another pair of sisters who shared a similar closeness: the late Queen Elizabeth and Princess Margaret.
“Like the bond shared between the Queen and Princess Margaret, they are genuinely best friends who understand each other and who Catherine can trust implicitly,” they said. “And like Princess Margaret, Pippa is the more outgoing of the two sisters, but that only adds to her ability to support her sister in her royal role.”
The two women are only 21 months apart and as children “bonded over their shared love of exercise and sport while both pupils at Marlborough College,” The Daily Express writes. In their twenties, the two were regulars on the Chelsea social scene, and were even roommates at one point, sharing a Chelsea apartment before Kate married Prince William in 2011. “The pair were often spotted on nights out together at popular London hotspots, including Mahiki and Boujis,” The Mirror reports. “After William proposed to Kate, she wasted no time in asking her sister to be her maid of honor in 2011.”
A source told The Daily Mail at the time “It’s all Kate, Kate, Kate for the moment, because [Pippa is] her closest ally and, genuinely, they are best friends,” they said. “But even if they weren’t, Kate would struggle to trust anyone who wasn’t family.”
In a previous NBC interview, Pippa said of her sister “I mean, obviously she has pressures she’s taken on and things,” she said. “But we spend a lot of time together. We still do a lot together as a family. We have a very normal, sisterly relationship. We’re very close. And, you know, we support each other and get each other’s opinions and things.”
After Pippa, her husband James Matthews, and their kids Arthur, Grace, and Rose moved to Berkshire—which The Daily Express describes as “just a stone’s throw from the Wales’s royal residence, Adelaide Cottage in Windsor”—the sisters have become even closer, and after Kate’s cancer diagnosis earlier this year, “Pippa has been more than a shoulder to cry on—she’s been a powerful tower of support for her sister during her cancer treatment,” the outlet writes.
The entire Middleton family of five—sisters Kate and Pippa plus younger brother James and their parents Michael and Carole—are all famously close. “The three siblings are incredibly tight,” a source told The Times. “Pippa not only as a sister but as a best friend she can confide in. They are extremely loyal to one another.”
James, for his part, wrote a moving message on Instagram in the hours immediately following Kate’s March 22 announcement that she was receiving treatment for cancer; it read “Over the years, we have climbed many mountains together,” he wrote alongside a photo of them beside a mountain range. “As a family, we will climb this one with you, too.”
Kate’s closeness with Pippa makes sense why she’d want her by her side for Wimbledon, only her second public appearance of 2024. As for William, though he is famously estranged from his only sibling, younger brother Prince Harry, Us Weekly reports that his older cousin Zara Tindall is the “big sister” William never had, and a source added that Princess Anne’s only daughter is also close to her uncle, King Charles. She “has been a huge help to both him and William during his awful year,” they said. “Zara has been a breath of fresh air. She’s loved by the public as she’s fun and unpretentious.”