When it comes to the Queen's closest aides, none appear to be more trusted than her right-hand woman Angela Kelly.
She has been the monarch's personal advisor and senior dresser, working with her closely every day, for almost 30 years.
It seems the two women know each other inside out and reportedly love nothing more than chatting over a cup of tea.
In 2019, Angela got "extraordinary permission" from her boss to release the book - The Other Side of the Coin - which featured never before seen behind-the-scenes photos and insider information about life at Buckingham Palace.
And just yesterday, it was announced that an updated version of the book is to be released next month to coincide with Her Majesty's Platinum Jubilee celebrations.
In the original book, Angela shared several secrets about the Queen and what life is like behind palace walls. Here we take a look at some of these - and look at what she will be revealing in the updated version of the book...
Trick for shoes
As the staff member in charge of the Queen's wardrobe, Angela revealed in her book many handy tips and tricks she uses when it comes to looking after Her Majesty's clothes, accessories and jewellery.
Before the book was released, it had long been reported that Her Majesty employs an assistant to wear in her shoes.
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But in her book, Angela confirmed the reports and revealed that she's the "flunky" who does it.
She writes: "The Queen has very little time to herself and not time to wear in her own shoes, and as we share the same shoe size it makes the most sense this way."
Most of the time, the Queen wears black low heeled shoes by shoemaker Anello & Davide, which she reportedly calls her "work shoes".
Love of make up
Another secret that Angela divulged is that the Queen is a dab hand when it comes to applying her make-up.
In fact, she reveals how the monarch does her own make-up nearly every day - apart from on one occasion, the day her Christmas message is filmed.
Angela reveals: "You might be surprised to know that this is the only occasion throughout the year when Her Majesty does not do her own make-up."
Instead, she enlists the help of TV make-up artist Marilyn Widdess.
Queen asked for line in James Bond sketch
Back in 2012 when London hosted the Olympics, one of the highlights of the opening ceremony was the Queen's sketch with James Bond, played by Daniel Craig.
Angela recalled being presented with the plan for the skit, devised by film director Danny Boyle, who had been tasked with coming up with a stunning ceremony to open the 2012 Games.
And she explained Her Majesty was keen for a speaking part during her cameo appearance with 007 to celebrate all things British.
"There are few occasions on which Her Majesty will agree to break protocol, but in 2011 when film director Danny Boyle approached the Royal Household, he had a request to make that we simply could not refuse," Angela writes in her book.
"She was very amused by the idea and agreed immediately. I asked then if she would like a speaking part. Without hesitation, Her Majesty replied: 'Of course I must say something. After all, he is coming to rescue me'."
Ms Kelly said she asked the Queen if she would like to say: "Good evening, James", or "Good evening, Mr Bond", with the monarch choosing the latter.
She said: "Within minutes, I was back in Edward's office delivering the good news to Danny - I think he almost fell off his chair when I said that the Queen's only stipulation was that she could deliver that iconic line: 'Good evening, Mr Bond'."
Inappropriate photo
The Queen has posed for thousands of pictures since she took the throne in 1952.
But according to Angela, there was one pose she'd always longed to have a portrait taken in, but was never allowed.
In her book, she revealed Her Majesty wanted a picture taken in a more informal pose, like with her hands in her pockets, but the Queen Mother and Queen Counselors had always asked her not to do as they were "not suitable for the public eye."
But Angela, who had known about the Queen's "secret wish" for several years, had a clever idea that would make it come true.
She says: "I wondered if I might have a wonderful opportunity to make the Queen's wish come true."
She nervously asked the Queen if she would "do her a favour" and pose with her hands in her pockets for an image in the book.
Angela said: "The Queen looked at me in amazement as I asked whether she knew the implications of the photographs.
"She didn't take long to answer: yes, she would do it and, yes, she was sure."
Christening gown trick
As well as being tasked with taking care of the Queen's clothes - and even designing some herself - Angela has also taken charge of items worn by several members of the Royal Family.
From 1841 until 2004, all royal babies had worn a christening gown made from Honiton lace for the children of Queen Victoria.
But as the gown had become rather old, the Queen commissioned Angela to create a replica version for use in the future.
So how did she get the colour of the gown just right? Yorkshire Tea.
In her book, Angela wrote: "She writes: "Together, we sourced lace to complement that being made in Italy, and to make sure it looks authentic we dyed it in Yorkshire tea (the strongest, as we all know).
"We placed each piece of lace in a small bowl, from the Dressers' kitchen, filled with cool water and a tea bag, and left it for about five minutes, checking regularly until the colour was perfect."
The gown has since been worn by the likes of Prince George, Princess Charlotte and Harry and Meghan's son Archie.
Cruel prank
As well as sharing tricks and tips, Angela also gave an insight into her close bond with her boss - and how they share a similar sense of humour.
Angela explained that the Queen was desperate to see a kookaburra bird during their Royal Tour to Australia in 2006.
She didn't have any luck spotting one, so when Angela saw a cute toy version during a trip to a market in Sydney while her boss was at an engagement, she decided to buy it for her.
But rather than just giving it to her, she decided to have a bit of fun first.
When she got back to Governor's House, where they were all staying, she placed the toy in a little cage on the balcony outside her room.
When the Queen got back Angela told her she had spotted a "funny looking grey bird" through the window.
"The Queen looked outside and shouted 'It's a kookaburra!' I went to open the cage doors and she said loudly 'No! Don't do that! It will fly away!' and was behind me in a flash.
"Turning to her Majesty while trying to keep a straight face, I solemnly told her it was dead."
The Queen looked "horrified" until Angela walked towards her with outstretched arms and said "April Fool".
"She had only two words for me: "You're sacked. I was laughing uncontrollably as her Majesty turned to His Royal Highness and said "Do you know what she has just done to me? Angela has had me!".
The Queen took the little toy back to Windsor Castle with her and it now lives on the back of the sofa in her private living room.
Queen enjoyed Michelle Obama's hug
In 2009, former First Lady of the US Michelle Obama broke the so-called no touch rule when she appeared to put her arm around the Queen, with royal experts calling it an "extraordinary" gesture.
But according to Angela, Her Majesty quite enjoyed the touching moment with Mrs Obama.
She wrote in her book: "Much has been made about the meeting between Michelle and Her Majesty when an instant and mutual warmth was shared between these two remarkable women, and protocol was abandoned as they stood closely with their arms around each other's backs.
"In reality it was a natural instinct for the Queen to show affection and respect for another great woman and really there is no protocol that must be adhered to."
"When fondness is felt or the host of a State Visit goes to guide her Majesty up some steps, it truly is about human kindness and this is something the Queen will always welcome warmly."
New secrets
When the updated version of Angela's book is released next month, it will feature a new chapter that has covered the last two years.
So what can we expect in it?
Well according to publisher Harper Collins, the update will see Angela will talk about the royal household's isolation during Covid-19 lockdown at Windsor Castle, which saw her taking on new roles such as cutting and setting the Queen's hair.
The chapter will also cover Prince Philip's funeral, the Queen's first public engagement post-lockdown and a look ahead to June's Platinum Jubilee celebrations.
Katya Shipster from Harper Collins said: "We are so proud to be Angela Kelly's publishers. We wanted to commemorate the extraordinary occasion of the Queen's Platinum Jubilee with this beautiful new edition, as well as bring the book right up to date following the unprecedented events of the past two years.
"It tells the story of the Royal bubble as well as the lengths Angela and the Royal Household went to, to ensure the safety of our monarch. There is no better look at what goes on behind the pomp and circumstance than this wonderful book."
