Just like her 70 years of service to her country, the Queen was equally as fiercely loyal to her hair style, which remained somewhat steadfastly unchanged over the years.
The perfectly coiffed do, gave the late monarch one of the most recognisable and iconic silhouette's in the world, appearing on bank notes, stamps and across various royal memorabilia.
But there's actually an important reason the Queen stuck to her statement style and it’s the same reason she always wore bright colours.
According to her daughter-in-law Sophie, Countess of Wessex, the reason for the colour bright dressing is because the Queen wanted to ensure members of the public can catch sight of her through the crowds.
"She needs to stand out for people to be able to say 'I saw the Queen'," the royal said in the documentary The Queen at 90.
"Don't forget that when she turns up somewhere, the crowds are two, three, four, 10, 15 deep, and someone wants to be able to say they saw a bit of the Queen's hat as she went past.”
Making herself instantly recognisable was also reportedly a factor in the Queen's choice to stick with the same hairstyle.
In fact, according to some insiders, the monarch is believed to have insisted on her hair being entirely symmetrical, so that whatever side you saw her from, that iconic profile remained the same.
"I met somebody, who was the Queen's hairdresser, who said that what she likes and insists upon is that her hair is entirely symmetrical," broadcaster Dame Esther Rantzen said, as reported by Daily Mail's Eden Confidential.
She continued: "Her hair has to look the same from one profile and then to the other, so that whatever side people are watching her from, her hair always looks exactly the same."
So what exactly was the Queen's style?
"Queen Elizabeth II was known for a classic shampoo and set, which would have been representative of the time she was crowned," Neil Moodie, founder of the Neil Moodie Studio tells Yahoo UK.
"This then became her signature style throughout the years. She embraced her natural curls, but these were more refined, and displayed symmetry at all times. This meant that whether she was photographed on the left or right, her style remained consistent."
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Nicole Petty, hair expert for Milk + Blush believes the unchanging nature of her iconic look is part of the reason that the British public adore her style, associating it with being "quintessentially the Queen".
“In her reign of 70 years, the Queen’s hair has remained just as steadfast as her ruling, with a few small exceptions over the years," she explains.
"The Queen’s style allowed her to embrace her natural curls, kept off the shoulder – usually sitting around her jaw length – and always perfectly coiffed."
So has the Queen ever deviated from her iconic style?
In June earlier this year in pictures shared to The Royal Family Instagram account, the Queen wore a pretty, floral dress to meet the right Honourable Margaret Beazley, Governor of New South Wales.
But it was her hair switch up that captured the attention of royal fans.
"She changed her hair, so sweet," one wrote on social media.
"Did Her Majesty get a haircut?" another asked.
"Oh I can see her new hairstyle, it's shorter than usual," another fan agreed.
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Petty says Her Majesty also experimented with the volume of her coiffure.
"Most notably during the 1980s, her hair had much more body and height – very in fitting with the more experimental styles of the time," she explains.
"Her hair also became much fluffier in her later years, yet remained just as well styled as in her youth."
As for her colour, Petty says the monarch was rumoured to have stopped dying her chocolate locks during the 1990s,"allowing her brown hair to give way to her stunning signature white hue.”
Of course there was also the time the Queen's most trusted aide had to cut and set her hair during the COVID-19 lockdowns.
In the updated version of her bestselling book The Other Side Of The Coin: The Queen, the Dresser and the Wardrobe, Angela Kelly detailed her experiences of taking on the role of cutting and setting the monarch's hair during the coronavirus pandemic.
In the new chapter excerpted by Hello! magazine, Kelly wrote, "From March 2020 onwards I washed The Queen's hair every week, set and styled it, and even trimmed it when needed. My team named it Kelly's Salon."
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But the new found role didn't come without some trepidation from Kelly.
"During the first two weeks, I was shaking," she said. "I had only done her hair once or twice before while on board the Royal Yacht Britannia. The Queen was so kind as she advised me on the very specific way to put the rollers in."
As Kelly grew more comfortable in her new duty, the Queen wasn't afraid to voice her opinions.
"As I grew in confidence I'm sure The Queen thought I was a professional and started shouting at me, 'Don't do that, do it this way. That's right, you've got it, don't change it.' I was thinking, goodness me, I need a gin and tonic," Kelly said.
"So while The Queen was under the dryer I said to her, 'I'm off for a stiff drink because this is so stressful, getting it just right for you.'"