King Charles is preparing for a major staffing shakeup.

The monarch’s right-hand man, Sir Clive Alderton, will step down from his role as principal private secretary next year, it was revealed on Monday, July 27. His departure will coincide with his 60th birthday and come after 20 years of working for the Royal Household.

Alderton has played a massive role in supporting King Charles, 77, notably in preparing for the sovereign’s 2022 accession to the throne, 2023 coronation ceremony and the first years of his reign.

Alderton said in a message to staff, shared with PEOPLE, “It has been the greatest imaginable honor to serve the King and Queen in my present role through such historic times and with unforgettable humor along the way. That support will continue, in a less formal capacity, for all of my life.”

A palace spokesperson added that King Charles, 77, and Queen Camilla, 78, “are deeply grateful to Clive for his tireless support and wise counsel over the years and for the enduring loyalty that will ensure a smooth transition to his successor.”

The palace will start the recruitment process for his successor, who will begin in the spring or summer of 2027.

According to the U.K. government’s website, Alderton joined the Foreign Office in 1986 and served in various diplomatic posts in Poland, Belgium, Singapore and France.

He joined the Royal Household in 2006 as a deputy private secretary to Charles and Camilla, then the Prince of Wales and Duchess of Cornwall, before becoming their private secretary for Foreign and Commonwealth Affairs. He was then Queen Elizabeth’s ambassador to the Kingdom of Morocco and her non-resident Ambassador to the Islamic Republic of Mauritania from 2012 until 2015 before serving as Charles and Camilla’s principal private secretary.

In his 2023 memoir, Spare, Prince Harry referred to three key staffers in the Royal Household by insect nicknames, with Alderton widely believed to be “the Wasp.”

“The Wasp was link, charming, arrogant, a ball of jazzy energy,” Harry said. “He was great at pretending to be polite, even servile. You’d assert a fact, something seemingly incontrovertible — I believe the sun rises in the mornings —and he’d stammer that perchance you might consider for a comment the possibility that you’d been misinformed: Well, heh-heh, I don’t know about that, Your Royal Highness, you see, it all depends what you mean by mornings, sir.‘ “

“Because he seemed so weedy, so self-effacing, you might be tempted to push back, insist on your point, and that was when he’d put you on his list,” Harry added. “A short time later, without warning, he’d give you such a stab with his outsized stinger that you’d cry in confusion. ‘Where the f— did that come from?’ “

Alderton also sits on RAVEC, the Royal and VIP Executive Committee, a 10-person committee that determines official protective security for public figures in the U.K. Since stepping back from his royal role in 2020, Prince Harry lost his police protection in his home country, something he has fought to reinstate to no avail.

PEOPLE understands that a review of the Duke of Sussex’s security arrangements by RAVEC had yet to conclude as of late June. Representatives for Prince Harry say RAVEC’s own terms of reference call for a Risk Management Board review at least once a year, but Harry’s last review was conducted nearly seven years ago.

In an interview in May, following the failure of his appeal, Prince Harry implied to the BBC that he believed his father could influence the decision despite the fact that the palace has consistently denied that the King has the power to have that security reinstated.

Alderton’s replacement will also take his spot on RAVEC.