Let's take a look back at the extraordinary couple and why they remain so close
According to HELLO! magazine, Fergie and the second son of Queen Elizabeth and Prince Philip, met through Princess Diana.
The publication reports that Andrew and Fergie knew each other as youngsters, however, fell out of touch during their teen years. It wasn't until Diana invited Sarah to a party at Windsor Castle that the Duke and Duchess of York rekindled a friendship, which quickly developed into a romantic relationship.
The couple had a whirlwind romance, with Andrew proposing in March 1986. The royals then married at Westminster Abey on 23 July 1986.
Fergie and Andrew welcomed their daughters soon after, Princess Beatrice in August 1988, and then Princess Eugenie in March 1990.
Unfortunately, it was soon after Eugenie's birth that the marriage started to crumble.
Fergie and Andrew decided to legally separate in 1992. Reportedly the decision to separate was due to his demanding job in the navy, which meant the couple only saw each other for 40 days for a year for the first five years of their marriage.
There were also rumours surrounding Fergie's adultery.
Reflecting on that time and her subsequent decision to divorce after being separated for a number of years, Fergie told Harper's Bazaar in a 2011 interview that all she desired was friendship and not money.
"I didn't want a divorce but had to because of circumstance."
"When I met with Her Majesty about it, she asked, 'What do you require, Sarah?' and I said, 'Your friendship,' which I think amazed her because everyone said I would demand a big settlement. But I wanted to be able to say, 'Her Majesty is my friend'— not fight her nor have lawyers saying, 'Look, she is greedy.' I left my marriage knowing I'd have to work. I have."
It seems Fergie got her wish!
