The embattled royal's departure from official life has been swift and "ruthless," Lacey tells PEOPLE

The fallout from Prince Andrew’s disastrous interview about his friendship with convicted sex offender Jeffrey Epstein has seen his official royal role collapse to almost nothing in 10 days.

Just days after Andrew, 59, announced he was “stepping away” from public duties for the “foreseeable future” on Nov. 20, it now seems only a matter of time before it is confirmed that he will not continue with anything official ever. “His entire public existence has been wiped out by his own behavior,” royal historian Robert Lacey, author of The Crown: The Official Companion Vol. II, says in this week’s issue of PEOPLE.

Prince Andrew BBC Interview
Prince Andrew with BBC journalist Emily Maitis during his interview regarding Epstein.
| Credit: BBC/Mark Harrison

Last week, he was forced to pull out of a trip to Bahrain for an international meeting of his Pitch@Palace organization, which promotes entrepreneurs and new ideas largely in the tech sector. And his office is set to move out of Buckingham Palace and center around Pitch rather than official royal work.

For more on Prince Andrew’s ouster from official royal life, pick up this week’s issue of PEOPLE

The moves to distance the monarchy from Andrew’s connection with Epstein have been been speedy, following discussions between the prince’s mother Queen Elizabeth, her eldest son Prince Charles and other senior royals. The decision “shows that the royals can move very swiftly and very ruthlessly,” says Lacey.

22/11/2019. Windsor, UK. Prince Andrew, The Duke of York (second left), is seen riding a horse with Queen Elizabeth II (second right) in the grounds of Windsor Castle estate. Prince Andrew is stepping down from official duties following a Newsnight interview on his relationship with Jeffrey Epstein.
Prince Andrew (center) riding with his mother Queen Elizabeth (second from right) in Windsor on Nov. 22.
| Credit: Ben Cawthra/Sipa

But the Queen, 93, has made sure that her personal support remains with her son. He accompanied her on horseback with two escorts on Nov. 22 — something she would know would likely be captured by photographers and send a signal that, despite her decision to ask him to withdrawn from public work on her behalf, she still stands by him.