Queen Elizabeth's Hats Show She Is 'Indentured to Service,' Fashion Expert Says in New Book

"It's a reminder that the Queen is indentured to a service, to a job," British historian Robert Lacey explained to Elizabeth Holmes for her new book, HRH: So Many Thoughts on Royal Style

Even if you haven't seen photos of Queen Elizabeth's most recent daytime appearance, you can probably envision what she was wearing: a vibrantly-hued coat, a matching hat, black shoes and a bespoke bag.

While each piece is part of the monarch's royal "uniform," her hats hold a special significance.

"Very few modern women wear a hat as part of their work uniform, aside from perhaps members of the armed forces," British historian Robert Lacey explained to fashion journalist Elizabeth Holmes for her new book, HRH: So Many Thoughts on Royal Style.

"'It's a reminder that the Queen is indentured to a service, to a job,'" he said, according to the book, which published on Tuesday.

Queen Elizabeth. Ben Stansall - WPA Pool/Getty

Holmes, who spent more than 10 years as a business and fashion journalist for The Wall Street Journal, gained a massive following for her Instagram series, "So Many Thoughts," in which she explored royal fashion. After interviewing a number of fashion experts and designers, some of whom have worked intimately with the royal family, Holmes expanded her analysis of the "power" of royal fashion to create HRH, a deep dive into the branding and fashion journeys of Queen Elizabeth, Princess Diana, Kate Middleton, the Duchess of Cambridge and Meghan Markle, the Duchess of Sussex.

The Queen. Mark Cuthbert/UK Press via Getty Images

"What I find so fascinating about royal style, in particular, is the ways in which these women use their clothes. A big part of their job is to appear in public. They don't give revealing interviews or do all that much talking" Holmes tells PEOPLE. "Their clothes are so beautiful, but they mean a lot, too... It's proof of the power of fashion."

In HRH, Holmes traces Queen Elizabeth's styling choices from her childhood to her coronation in 1952, to her makeover in the late '90s, which led to her brightly-colored coats.

"The Queen is conscious that she must be easily visible to as many people as possible when she is out and about, so I choose mainly striking colors that will be easily seen," Angela Kelly, the Queen’s longtime dressmaker, wrote in her 2019 memoir The Other Side of the Coin: The Queen, The Dresser and the Wardrobe.

Beyond the bright colors, what's most noticeable about the Queen's style is how little it's changed.

"Nobody dresses like the Queen. And nobody probably ever will," Holmes says. "It is a very singular look that she has devised, and she's committed to it.

"I loved talking about the Queen's style with some really wonderful fashion experts, [who explained] that it's not her job to be trendy," Holmes continues. "Can you imagine how unstable right now it would be to see the Queen flipping from one designer to the next, or trying out to different trends? There is something immensely calming in her consistency."

Queen Elizabeth may have her own unique style, but she shares fashion sensibilities with her granddaughter-in-law, Kate. They both value clothing for its functionality and view it as part of the "job" of being a royal. Since joining the royal family in 2011, Kate has grown increasingly conscious of the power of her clothing choices — and more confident, Holmes writes.

The Queen at Kate Middleton and Prince William's wedding in 2011. Kurt Krieger/Corbis via Getty Images

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"As she's grown into her role, we see her in some very queen-like outfits," Holmes says. "The candy-colored coat dresses are meant to be seen, the ways in which she still abides with some of the more formal fashion practices of wearing even nude pantyhose, or hairnets on occasion — you could just sort of imagine [the Queen and Kate] getting dressed to go to work. Because that's what this is, that's just the job."

While all of the royals are known for re-wearing outfits, the Queen and Kate seem to do this quite often, Holmes writes. They both value frugality.

"What’s really struck me is her love for the simple things in life," Kate said of the Queen during the 2016 documentary Our Queen at Ninety, which was also cited in HRH. "You would expect a lot of grandeur and a lot of fuss. Actually what really resonates with me is her love for simple things, the lack of fuss — and it’s a special quality to have."

Both women are also very aware of what's expected of them during public appearances, Holmes explains.

"These women are operating within guard rails. They are not just celebrities, who can do or wear what they please. They are part of this institution and working in service to the crown," she says. "Their appearances come with a certain set of expectations. People want them to be fancy and worthy of their royal titles, but also frugal, responsible stewards of the taxpayer money."

Kate Middleton. Getty (3)

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She adds: "That line of stylish and sensible is actually really hard to walk. And I admire both of them for the ways in which they've done it."

The Queen's imagery evokes a sense of authority, wealth and stability, Holmes writes. But Kate's fashion — for instance, rewearing a skirt suit and styling it with a bow in her hair ("Anybody can go out and buy spool of ribbon and tie a bow in their hair," Holmes says. "And so, you can have the Kate look, you can have that feeling of dressing like a Duchess so easily.") — has helped people reconnect with the monarchy.

"To see Kate wear something repeatedly is a reminder that she is a woman with a closet, and her clothes are part of her job, and she is just like us," Holmes says. "The ways in which Kate helped a new generation of royal followers see themselves and this family through her clothing choices has had a profound effect on the affection that we have for the monarchy."

HRH: So Many Thoughts on Royal Style is on sale now.