LONDON — Costume designer Kasia Walicka Maimone grew up with Leo Tolstoy’s “Anna Karenina” in her native Poland. The Russian classic is part of her “cellular structure” and she recently reread the novel set in the late 19th century.

The period has had a lasting impact on her and it’s also the time frame of the HBO series “The Gilded Age,” about New York City’s elite as they shuffle from opera houses to fancy luncheons and beyond.

Maimone has been working on the historical drama for over five years and nothing is short of grandeur as she costumes characters based on New York’s famous families: the Astors, the Goelets, the Livingstons, the Van Rensselaers and the Vanderbilts.

“I live in New York and it’s such a celebration of the city and getting to know the history of New York intimately,” she said in an interview, detailing that she works on 5,000 to 7,000 costumes a season with her team, which on a regular day is made up of 65 people and can go up to 200 on a big shoot day.

Now for the third season, Maimone has had to look beyond the fashions and parameters of the city, as Gladys Russell, played by Taissa Farmiga, marries into British aristocracy and becomes a duchess. Her character takes inspiration from Consuelo Vanderbilt’s marriage to Charles Richard John Spencer-Churchill, 9th Duke of Marlborough.

Gladys clashes with the duke’s sister, Lady Sarah, played by Hattie Morahan, as she teaches her a new way of life in England and living in a country house.

“My obligation is to make sure that each character is different and that they are defined by what they are wearing. It was very obvious what to do with Lady Sarah, she needs to be zipped up and conservative. She continuously [wears] a riding outfit with classic lines, which clashes with Gladys’ newest fashions,” Maimone said.

Lady Sarah is costumed up to the neck in dull tones and sharp collars, while Gladys arrives at Sidmouth Castle wearing dresses made from red and turquoise lace, yellow jacquard and baby blue tartan.

Gladys is a mirror of her mother, Bertha Russell, a fictionalized version of Alva Vanderbilt, a newcomer in New York City society who is clawing her way to the top with extravagance and somewhat bad taste to the old guards of the city.

The Russell family’s costumes are daring and years ahead of their time.

“The old guard famously bought the same dresses from the House of Worth and then kept them in the closets for two years until the seasonalism quietened, but Bertha has no problem with that kind of bad taste as she’s happy to manifest it,” Maimone said.

It’s what Gladys does when she arrives in England — in one scene, she wears diamond stars in her hair — that Lady Sarah frowns upon.

Maimone also understands that not everything is historically accurate — there’s always going to be an element of entertainment. “We crank it up a bit more than what it would have been in real life and that’s my job. There’s a playfulness with the material,” she explained.

Her research into 19th-century New York fashion is as detailed as any history degree and spans across texts, books, magazines and art.

Many of Gladys’ costumes take their cues from the paintings of the American artist John Singer Sargent, who painted Consuelo Vanderbilt a few times during his lifetime.

Maimone’s attention to detail is precise — even to the secondary or one-off characters, such as Madame Dashkova, a spiritual medium, or Monica O’Brien, Bertha’s sister.

“She communicates with animals and she’s wearing a fox paw on her chest that she talks to. It was just a really fabulous exploration of what to do with a fortune teller,” she said, adding that in the case of O’Brien’s arrival in her old rags, it was about instantly letting viewers know that there was a history and disconnect between the sisters before they even came into contact with each other.

Nothing is put to waste on the expansive set of “The Gilded Age,” not even the costumes.

Maimone reuses all the pieces for the house staff and with the menswear she makes additional tweaks every season to move the costumes forward with the time period.

This season, Agnes van Rhijn, played by Christine Baranski, rewears many of her old dresses since losing her fortune and being dependent on her sister, Ada Forte, played by Cynthia Nixon, who has come into wealth but doesn’t change her costumes that much as she’s still in mourning.

The costumes of the show are a reflection of the storyline — many of the pieces are made in New York, but some are specially designed in Europe for the main characters.

But New York seems to hold a special place in Maimone’s résumé. She costumed the 2005 film “Capote,” based on Truman Capote, and the crime drama “A Most Violent Year,” depicting ‘80s New York.

“I studied English in Warsaw and when I graduated, I was quite lost and ended up living in New York City surrounded by this community of artists, who were extremely passionate about what they were doing. It was an awakening moment and I had been making clothes since I was a kid, so I ended up going to FIT, where I realized that [fashion] was the most natural language that I had and it was the first time that school ever made sense in my life,” she said.

Maimone had a hand working in theater and with dance companies and operas at that time and found her calling.

“I quickly noticed that I belong so much more in storytelling than in fashion because I’m very passionate about stories and discovering new worlds,” she said, remembering “Life Situations: Daydreams on ‘Giselle,’” a production she worked on with the modern dance choreographer Donald Byrd in 1995.

All roads lead back to the opera or stage for Maimone, who is costuming the upcoming biopic “Springsteen: Deliver Me from Nowhere,” starring Jeremy Allen White as Bruce Springsteen.