Sarah Ferguson and Prince Andrew were childhood friends who started a romance after meeting again at Royal Ascot in 1985.
The couple married on 23 July 1986, and over the next four years welcomed two adorable little girls, Princess Beatrice, and Princess Eugenie.
Beatrice was born on 8 August 1988, and her little sister Eugenie arrived on 23 March 1990, completing the famously down-to-earth family of four.
While Prince Andrew and Sarah separated in 1992 and divorced in 1996, they remain close to this day – and their little girls are now all grown up!
Beatrice is happily married to Edoardo Mapelli Mozzi, with whom she shares a two-year-old daughter Sienna, while Eugenie tied the knot with her long-term love Jack Brooksbank in October 2018. The couple have since welcomed two sons, August and Ernest.
Despite their changing personal lives, the two sisters are still as close as ever.
Take a look back at their best throwback pics from their childhood and beyond...
Horsing about, 1992
We love how Beatrice and Eugenie were often dressed in matching outfits as children. Here they are at the Royal Windsor Horse show in May 1992.
Royal bridesmaids, 1993
On 24 April, 1993, Sarah, Duchess Of York, held Princess Beatrice's hand as she and little sister Eugenie served as bridesmaids at their former nanny's wedding.
The sisters looked gorgeous in their extravagant dresses and floral headbands – which Eugenie quickly removed following the ceremony!
Sports day, 1993
Princess Eugenie loved her shades and hairbands as a youngster. Here she is supporting her older sister Beatrice at her school sports day in 1993, accompanied by mum Sarah and dad Prince Andrew. We love her striped red shorts and matching accessories. So cute!
Fairground chic, 1993
There's nothing Beatrice and Eugenie seemed to love more than dressing alike!
Here the two adorable girls go casual in baseball caps and varsity jackets in May 1993 at a fairground in Windsor.
First day of school, 1994
It was time for little Princess Eugenie's first day of school in September 1994.
Of course, when she made her Upton House School debut in Windsor, her big sis Princess Beatrice was right there by her side. This is just the cutest photo of the siblings!
Ski holiday, 1995
You can't look at Beatrice and Eugenie's childhood without seeing a glimpse of their royal cousins, Prince William and Prince Harry!
Here the foursome are seen in January 1995 during a ski vacation in Klosters, Switzerland. William, right, adorably helped Beatrice with the collar of her ski suit.
Matching boots, 1996
The Olsen twins had nothing on these two!
Holding hands with mother Sarah in July 1996, Princess Beatrice and Princess Eugenie showed off their colourful mid-1990s style in yellow boots, printed sarong skirts and cute matching bows in their hair.
Little ballerinas, 1999
Beatrice and Eugenie were sweet ballerinas as they arrived in matching purple tutus and elaborate makeup alongside their mother to the Santa's Starry Night Show at the Drury Lane Theatre in London.
The December 1999 show was to benefit the Children In Crisis charity founded by Sarah Ferguson.
Girl Power, 1999
Our 1990s selves can definitely understand Princess Beatrice's excitement! The royal, along with Sarah, Duchess of York and Princess Eugenie, got to meet the Spice Girls backstage at an Earls Court concert in December 1999. The look on Beatrice's face says it all really.
The Queen's Golden Jubilee, 2002
Eugenie and Beatrice, flanking their father Prince Andrew, were seated alongside their cousins Harry and William for the St Paul's Cathedral service in celebration of Queen Elizabeth II's Golden Jubilee in June 2002.
Skiing with mum, 2004
Smile, girls! In February 2004, teenagers Beatrice and Eugenie snuggled up with their mum for a sweet mother-daughter photo in Verbier, Switzerland.
Meeting Leo, 2004
The royal sisters had a red carpet moment with Hollywood star Leonardo DiCaprio at the premiere of his film The Aviator at the Odeon West End in December 2004.
