But since the birth of Prince William and Kate Middleton's third child Prince Louis last April, Fergie and Prince Andrew no longer need the Queen's permission to Wednesday now with the Duke pushed further down the line of succession.
But the Royal Foundation have not ruled out them working together with William and Kate in the future, including on the Heads Together mental health campaign.
TRH and Ms. Markle discussed the inspiration behind The Royal Foundation, the issues that are close to their hearts, and their ambitions for the future.
The foundation said the move was taken to "better align" the couples' charitable activities.
A spokesperson said that "any announcement regarding this review will be made in due course", but the rumor is that the official exit will come some time after Wednesday's board meeting. With the issue of mental health high on all four royals' list of priorities, it's a natural fit for the foursome to tackle together.
Cardi B Indicted By Grand Jury In Queens Strip Club Brawl Case
And she's also accused of siccing members of her crew on the women because she believed they had sex with her husband, Offset . A source told NBC New York that surveillance video exists of Cardi B picking up an ice bucket and throwing it at the sisters.
In March it was announced that Queen Elizabeth II had agreed to allow the Duke and Duchess of Sussex form their own new royal household, which coincided with them moving out of Kensington Palace and into their new home of Frogmore Cottage on the Windsor Castle estate ahead of the birth of their son, Archie.
Last February, the royals were dubbed the "fab four" by media when they appeared together for their first official engagement - a Royal Foundation forum - and Meghan only became its fourth patron in May a year ago when she married Harry.
Kate, 37, joined the venture when she became the Duchess of Cambridge in 2011, as did Meghan, 37, when she married Prince Harry past year.
Royal commentators said the move was the final act in the division of the couples' public duties. "The Duke and Duchess of Sussex will establish their own new charitable foundation with transitional operating support from The Royal Foundation".
In March, it was announced Harry and Meghan would be separating from William and Kate's Kensington Palace office and they have since set up their own household at Buckingham Palace. Given his position in the line of succession, Prince Harry will likely never be king, affording him more opportunities to pursue his own interests and passions.