What’s more, those who attended – specifically Prince Charles, Prince William and Prince Harry – were also required to be born into the British royal family.
As a result, spouses were off limits, which meant William’s wife Kate Middleton was not involved, as well as Charles’ wife Camilla, and the Queen’s husband Prince Philip.
The reason for the limited attendees explains why the Duke of Edinburgh was seen leaving Sandringham ahead of the historical meeting with Her Majesty.
While Meghan Markle was previously thought to have participated in the meeting via phone from Canada, it has since been reported that she wasn’t involved.
On Monday, Prince Philip was reportedly “furious” about having to leave Sandringham ahead of Charles, Harry and William’s arrival.
According to The Sun, the Duke of Edinburgh was reportedly not only angry about Harry and Meghan’s shock decision, but also having to flee the Sandringham estate.
Footage of the Duke being driven out of the Norfolk estate grounds ahead of the Queen’s crunch talks shows the 98-year-old looking far from impressed.
A royal source told the publication: “To say that the Duke feels let down would be a considerable understatement. He is deeply hurt.
“He has left the Queen in absolutely no doubt about how he feels. Philip has accused Harry and Meghan of lacking respect and he is weary of their behavior,” the source added.