Royals The Sweet Story Behind One of Kate Middleton and Princess Charlotte's Twinning Favorites A go-to designer for Kate Middleton and Princess Charlotte tells PEOPLE that having a princess wear her pieces is "hugely exciting every single time" By Monique Jessen Published on September 22, 2021 12:27 PM Share Tweet Pin Email Princess Charlotte and Kate Middleton on Christmas Day 2019. Photo: UK Press Pool/UK Press via Getty Images When Princess Charlotte wore a mini-me version of mom Kate Middleton's favorite winter boots, it was a moment years in the making. "I first designed them a very long time ago and Kate actually bought them when she was working at Jigsaw as a buyer," British shoemaker Penelope Chilvers reveals to PEOPLE. "I don't think they ever sold them in the end, although I did sell dance shoes to her." More than a decade later, the same boots made their way onto the feet of her daughter Charlotte, who debuted them last Christmas for the Cambridge family's annual festive photo when mother and daughter posed with Prince William, Prince George and Prince Louis atop hay bales in a country-casual-themed photo shoot. Kate and William's 2020 Christmas Card. Matt Porteous/The Duke and Duchess of Cambridge/Kensington Palace/PA/WPA Pool The fleece-lined, mid-calf brown leather boots with distinctive leather tassels are very similar to Kate's knee-high Long Tassel Boot, which she has been wearing since her college days (17 years to be precise!). Shop Like a Royal This Fall! An early Christmas present from Kate, the Mini Tassel Boot — made in the same artisanal way as her own — has since been added to the main collection. Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more! Made in Spain using traditional manufacturing techniques, skilled artisans use a combination of vintage machines (that are more than 100 years old!) and hours of handwork as part of a 70-step process to complete each boot. "The boots become like a second skin; they mold to your foot and become like dependable old friends," says the designer, who adds they will last a lifetime if you care for them well. Indeed, they have clocked up many miles for Kate who first wore them in 2004 at the Blenheim Palace Game Fair, the same year that her relationship with William became public knowledge and the same year that Chilvers launched her eponymous label. "That was probably the most exciting time that she ever wore them for me and it just went viral," says Chilvers. Kate Middleton at Blenheim Palace in 2004. Stephen Lock/Shutterstock "She's the epitome of our customer because she loves the healthy outdoor life, she loves the countryside, and I love how she often wears them to talk about conservation," says Chilvers. "She wore them on the beach in Wales when they were helping to collect rubbish and in Canada in that conservation area and Bhutan, which is also a protected landscape — it might be a coincidence, but it does seem to go hand-in-hand with the sustainable message that we share." Kate Middleton at various events in her Penelope Chilvers boots. For more insights on Kate's boots from Penelope Chilvers, plus additional exclusive royal style, check out PEOPLE Royals special issue, out now! While Kate has several similar styles from the brand, it's the versatile tassel boot in conker brown that she seems to love the most and it's a best-seller for the brand. "She's got a few pairs I think. She's been a customer for a very long time — one of my first!" says Chilvers, who reveals she is introducing the style in a wider calf size for the first time this fall. Despite the number of royal appearances, Chilvers says she still gets a buzz when Kate wears her design. "It's been fantastic for us, we feel so lucky and when Kate wears them, it's all hands on deck in the office — it's hugely exciting every single time."