Princesses Beatrice and Princess Eugenie appear inseparable.
During royal events the daughters of Prince Andrew, Duke of York, and Sarah Ferguson, Duchess of York the sisters are always spotted side-by-side, but what's Beatrice and Eugenie's relationship really like? Do they share clothes, do they bicker and argue, or do the sisters get along famously?
They may be known for their memorable outfits and even more unforgettable hats, but there is a lot more to this sisterly relationship. And as Princess Eugenie prepares to welcome her first child with husband Jack Brooksbank any day now, there's no doubt her big sister will be around to help support the new family more than ever.
From their special nickname for each other, to living together, this is what you need to know, and may not know, about Princess Beatrice and Princess Eugenie's relationship.
Princess Beatrice and Princess Eugenie are the daughters of The Queen's second son Prince Andrew, Duke of York, and his ex-wife Sarah Ferguson, Duchess of York.
Beatrice, 32 (born 8 August 1988), is the eldest of the two sisters, Eugenie is 30 (born 23 March 1990).
Before Eugenie and her husband Jack Brooksbank moved in together, the sisters lived together in a four-bedroom apartment at St James's Palace.
It's believed Beatrice lives still lives at the St James's Palace property in London with her husband Edoardo Mapelli Mozzi.
Meanwhile it's been reported that Eugenie and Jack recently relocated from Frogmore Cottage in Windsor - which was lent to them by Prince Harry and Duchess Meghan - to Eugenie's parents Prince Andrew and Sarah Ferguson's Royal Lodge in Windsor.
In 2008, just before her 18th birthday, Eugenie gave her first media interview to The Telegraph, where she explained how she and her sister have very different personalities, yet they're differences make them a closer pair.
"We get on fantastically well, perhaps because we do and think different things," the Princess said.
"I am definitely not as polite as Beatrice, I have to say. I tell it as it is. I am shyer at first. Like, at a party I will say to Beatrice as we go in, 'Oh, you go first.' But then, when we're actually in, I am much louder and she is far more polite and solicitous."
Mum-to-be Eugenie has also been quoted saying, "I do have an occasional temper - I sort of inherited my dad's short fuse."
As well as different personalities, the royal sisters also have opposite tastes in style.
According to Eugenie, she's a little more low-key, while older sister Beatrice is a fan of the glitz and the glam.
"Beatrice loves her glamorous dresses and her hair being curly or big - like Mummy's - and I hate volume. I like my hair to be sort of flat. I like just throwing on a pair of jeans and generally being more understated. She is more 'Let's do the glamour.' We're chalk and cheese," Eugenie said.
"It's quite funny how, like most sisters, we sometimes fight about clothes. I always take her clothes back to school, for instance, which she hates. We had a screaming argument over a pair of Converse trainers that I took back, which she said were hers and I said were mine," Princess Eugenie told The Telegraph.
"And in the end I realised they were hers when I found mine behind the door. Like all sisters, we have silly arguments about unimportant stuff, but we do love each other to death."
Unlike some of the royal family, Princess Beatrice and Eugenie don't do official royal work and therefore aren't paid by the taxpayer. Instead, the girls have real-life jobs just like the rest of us!
Eugenie is a director at the contemporary art gallery Hauser & Wirth, while Beatrice has a job at US technology firm Afiniti as an outsourcing strategist.
Princess Eugenie and Beatrice have a close bond with each other and also their mother. The threesome even have a cute nickname for themselves, Tripod.
"What can't I live without? My family. That sounds cheesy, but I really can't," Eugenie revealed to Harper's Bazaar in 2006.
"Especially my mum. I wouldn't be able to make tough decisions without her. And my sister."
"My mum always says that we're the only ones who know exactly what's going on in each other's lives."
After the media mocked Beatrice for the outfit she wore to Prince William and Duchess Catherine's wedding, Eugenie stepped in to support her sister.
"There was a horrible article that had been written about Beatrice and she got really upset," Eugenie told Vogue UK.
"We were just about to step out and she had a bit of a wobble and cried. I was looking after her. And then about an hour later, I had a wobble and started crying and Bea was there for me."
In October 2018, Beatrice was her sister's maid of honour when she wed Jack Brooksbank at Windsor Castle. Dressed in an elegant royal blue frock, the royal read a touching passage from F. Scott Fitzgerald's novel The Great Gatsby, which described Jay Gatsby's enigmatic smile.
Two years later, the Eugenie stepped up to the plate when it was Beatrice's turn to tie the knot.
"Beabea - wow! I'm so happy for you my dearest big sissy and dear Edo. It's been a long time coming and you two are meant to be," Eugenie penned on social media shortly after news of her older sister's engagement was announced.
Princess Beatrice wed Count Edoardo Mapelli Mozzi in a top-secret wedding on Friday, July 17, at Windsor Castle in the midst of the COVID-19 pandemic. The pair tied the knot in a low-key ceremony attended by less than 20 guests after they were forced to cancel their original wedding date of May 29 due to the COVID-19 pandemic.