As two of the most senior royal women, the Princess of Wales and the Duchess of Edinburgh brought the glamour to King Charles' Coronation.
They both wore show stopping white gowns, ceremonial robes and dazzling headpieces and chatted animatedly during the royals' appearance on the Buckingham Palace balcony.
And just days later, they brought the glamour once again as they stood shoulder-to-shoulder, twinning in blue as they hosted a Buckingham Palace garden party for 8,000 guests.
Despite their 17-year age gap, both women seem to have a sweet and fun bond with the pair chatting away and giggling at events. Here we take a look at exactly what the two have in common and how their adorable friendship has blossomed...
Normal upbringings
One thing that Sophie and Kate may have bonded over is the fact they both had relatively normal upbringings.
Sophie grew up in a middle-class family like Kate without any of the trappings of royalty. Both women attended school then had experience of holding down regular jobs before marrying into the Firm.
Before Sophie married Edward in 1999, she worked in PR, while before Kate's wedding to Prince William in 2011, she was an accessories buyer at fashion chain Jigsaw.
On marrying their husbands, both women also had to learn to navigate royal life and carry out engagements, with both now being seen as major assets to the Firm.
Welcome to the family
As Sophie married into the Royal Family 12 years before Kate, it appears she was happy to show her the ropes of royal life.
And this has been evident on the rare occasions that the two women have carried out engagements together, according to body language expert Judi James.
She told the Express: "Sophie's formula does appear to have been copied by Kate too as ‒ so far ‒ she has managed to tread the very fine line of creating interest that is positive but not unmanageable.
"Many of the poses of the two women together show Sophie face-checking Kate with quite strong bouts of watchful-looking eye contact to suggest she's taking a semi-maternal approach.
"She also [has] raised eyebrows and what's called a 'pinging' smile that implies she wants to ensure Kate is enjoying herself.
"There is some mirroring when the two women walk together but it's primarily Sophie projecting the stronger signals of relaxed confidence while Kate smiles happily at her side."
Meanwhile, it was recently reported that Sophie and Kate were also willing to help out Meghan Markle after she joined the Royal Family and later spoke out about her struggle within the Firm.
But royal journalist Rebecca English wrote in the Daily Mail : "They both, I'm told, 'repeatedly' reached out to Meghan after she first spoke of her unhappiness in 2019.
"However, I am also told that both Kate and Sophie were 'rebuffed'."
'Naughty bond'
However, rather than just supporting each other through the drama and challenges of living in the royal spotlight, Sophie and Kate have also formed a naughty and fun friendship, according to a body language expert.
In one picture of the pair from the London 2012 Paralympics, Sophie can be seen throwing her head back in laughter as Kate giggles from underneath the hood of her coat.
And Judi told The Sun : "Kate looks delighted to have made Sophie laugh like this and the slight nose-wrinkling suggests she thinks she is being rather naughty here."
Another famous photo of the pair shows Sophie almost falling into Kate after she stumbles while climbing into a carriage at Royal Ascot in 2017.
In this instance, Judi added: "The two women meet face-to-face here and Kate’s raised brows and eyes widened in mock shock produce a matching, open-mouthed response from Sophie, showing those strong bonds of shared fun that clearly seem to exist when the two women aren’t out in public."
So what shared interests could be the basis of this friendship? Well, it seems fashion and photography.
Both women are keen amateur photographers with Kate taking many heartwarming snaps of the royals over the years, with Sophie also capturing a beautiful image of the late Queen and Prince Philip in 2003.
Meanwhile, the pair are also known for their enviable wardrobes, with Sophie reportedly indulging in some shopping for Kate.
According to designer Donna Ida, Sophie bought a jumpsuit from her brand in 2019 - and then bought another specifically for her nephew's wife.
Donna told the Daily Mail: "My friend, a stylist, is best friends with Sophie Wessex, and Sophie buys from us. She got our [£295] black Sadie jumpsuit for herself and then asked for one for Kate. She said: 'Kate wants one, can I get one as well?'"
Parenting admiration
But it's not all just light-hearted fun between the two women, it's also been reported that Kate greatly admires Sophie for the way she has brought up her children, Lady Louise Windsor and James, Earl of Wessex.
It has been claimed that Kate looks at Sophie and Edward with respect, given how they have juggled between being working royals and preparing their children for a future not already established for them.
In her book The New Royals: Queen Elizabeth's Legacy and the Future of the Crown, commentator Katie Nicholl writes: "Kate is said to admire the way Prince Edward and his wife, Sophie, are raising their children — Lady Louise Windsor and James, Viscount Severn — in the bosom of the Royal Family but prepared for life in the real world."