The Gilded Age often gets accused of being a show where “nothing happens.” The Julian Fellowes drawing room drama does, indeed, center around finely honed banter, petty social spats, and gigantic plumed hats rather than murder and mayhem. But for those of us who love a period piece (I’ll watch anything about the lives of the rich and infamous), there’s plenty of intrigue if you know where to look.

The show’s third season, which premiered on June 22, takes the delightfully low stakes up a notch, making the HBO Max sleeper hit this season’s must-see television—especially now that Love Island is finally over. The plot (if you could even call it one) centers around Gladys Russell (Taissa Farmiga), a railroad heiress and the daughter of the powerful and hungry-for-more society matron Bertha Russell. (This is Carrie Coon’s career-defining role—I will die on this hill.)

Gladys wants to marry a nice boy from down the street. Bertha wants her daughter to bag a Duke—and thus elevate her family’s status from robber baron to American aristocracy. It’s “keeping up with the Joneses,” a phrase actually coined during the Gilded Age in reference to writer Edith Wharton’s family, as only Fellows could write it: Rife with hoity-toity zingers, class commentary, and enough opulent gowns to keep any costume drama fan drooling. (Warning: there are some spoilers—fashion and otherwise—ahead.)

Through a masterfully orchestrated, if a bit toxic, combination of coercion, heartbreak, and iron will, Gladys finally agrees to marry the Duke of Buckingham. On July 13, the “wedding of the century,” as her mother Bertha puts it, unfolds in all its tragic glory in an episode titled “Marriage Is a Gamble.” Yikes! It’s a pivotal moment for the series, answering questions like, Will Gladys pull a runaway bride? (She doesn’t.) And, Will she cry at the alter? (She does.) And, most importantly, What will her mother make her wear?

On the fashion front, Gladys’s long-sleeved, rosette-covered wedding gown is straight out of a fairytale, making her less-than-happy ending all the more tragic. So, too, was the opulent guest attire, bridesmaid gowns, and historically accurate suiting worn by the rest of the cast.

Naturally, Costume designer Kasia Walicka-Maimone, who’s worked across the show’s three seasons, went fully custom for the big wedding scene. Using “a combination of historical research, paintings, and fashion references” as inspiration, she tapped a global village of makers and artisans to bring the vision to life. “Producing the bridesmaid dresses, wedding guests, and clergy took an extraordinary amount of assistant costume designers, shoppers, costumers, makers, milliners, and fitters,” she explains.

Take the wedding dress: The fabric was sourced in New York City’s garment district, as were the flower embellishments, which were painstakingly attached by hand. The dress itself was made in Italy by the team at Tirelli Costumi. Her veil? Made from lace sourced in England and created by milliners Camilla Chuvarsky and Rhyan Shipman. The show’s in-house team of tailors, led by Sue Bakula, fit and embellished the piece after it arrived from Italy. Topped off with jewelry by Pikkio (also sourced in Italy), the effect was romantic, striking, and opulent enough for a leading heiress.

In fact, a real-life socialite with a connection to the British royal family served as the fashion blueprint. “Consuelo Vanderbilt’s wedding to the Duke of Marlborough was definitely a source of inspiration,” adds Walicka-Maimone. “We did use it as a reference for our approach to certain elements of the wedding, like our bridesmaid dresses and the length of Gladys’s train,” she says. “Also, the overall feel of the wedding and the wedding dress being a day dress were directly inspired by Consuelo’s wedding.”

This historical heiress—and the Vanderbilt family at large—heavily influenced the show’s fictional Russell family. Much like The Gilded Age‘s matriarch, Bertha Russell, Alva Vanderbilt arranged a loveless “marriage of convenience” between her daughter and a British peer. After wedding the Duke of Marlborough, Consuelo Spencer-Churchill became a famously fabulous and deeply unhappy figure in Europe during the 19th century, influencing style, policy, and culture.

Sound familiar? Well, you’re not the only one who thinks so. Historians often draw parallels with a future member of the Spencer-Churchill family: Lady Diana Spencer. It’s worth noting that Princess Diana and Consuelo, in addition to their shared family tree, both wore dresses with long sleeves, lace trim, frills, and cascading trains on their wedding days. So did Gladys Russell.

Consuelo was, in more ways than one, the Princess Diana of her time. So if this season of The Gilded Age reminds you of The Crown, you’re not far off