Prince Williamis checking on his regiment on behalf of his grandmotherQueen Elizabeth.

On Saturday, the Duke of Cambridge took on the role of leading the Colonel’s Review — a military rehearsal for the Queen’s upcoming birthday parade, Trooping the Colour.

As part of his royal duties, William was on hand to pass the Irish Guards fit for their big moment as part of the Queen’s Platinum Jubilee celebrations next week.

Prince William.BEN STANSALL/AFP via Getty

Britain’s Prince William, Duke of Cambridge rides a horse as he arrives at the Colonel’s Review at Horse Guards Parade in London on May 28, 2022. - The Colonel’s Review is identical to Trooping the Colour, the Queen’s annual birthday parade. (Photo by Ben Stansall / AFP) (Photo by BEN STANSALL/AFP via Getty Images)

“The purpose of the Colonel’s review is to decide that they are ready for Her Majesty,” an army source tells PEOPLE.

The Irish Guards are trooping their color — or flag — at the annual birthday parade for the Queen next Thursday. It is one of the main events of the Queen’s Platinum Jubilee celebrations next week, which commemorates the monarch’s historic 70 years on the throne.

Britain’s Prince William, Duke of Cambridge salutes as he rides a horse across the parade ground during the Colonel’s Review at Horse Guards Parade in London on May 28, 2022. - The Colonel’s Review is identical to Trooping the Colour, the Queen’s annual birthday parade. (Photo by Ben Stansall / AFP) (Photo by BEN STANSALL/AFP via Getty Images)

William, as holder of the honorary position of Colonel of the regiment, was tasked with looking over the parade. His role is to evaluate the troops to see if they are ready for Thursday.

DuringTrooping the Colour, more than 1,500 soldiers and 350 horses will carry out complex battlefield drill maneuvers to a program of music. In this special year, various musical tributes are planned for the Queen, including “Long Live Elizabeth.”

Prince William at last week’s inspection.Hollie Adams/Getty

LONDON, ENGLAND - MAY 28: Prince William, Duke of Cambridge, Colonel of the Irish Guards, leads the Colonels Review on Horse Guards Parade on May 28, 2022 in London, England. The Colonel’s Review is the final evaluation of the Trooping the Colour parade before the event which will take place on Thursday, June 02, in celebration of Queen Elizabeth II’s Platinum Jubilee. This year, it will be the Irish Guards Trooping their Colour, with the Duke of Cambridge evaluating the parade in his role as the regiment’s Colonel. (Photo by Hollie Adams/Getty Images)

Last week, Williampresented the 1st Battalion Irish Guardswith their new colors (flags) during a ceremony at Windsor Castle as a prelude for the big ceremony next Thursday.

BEN STANSALL/AFP via Getty

Britain’s Prince William (R), Duke of Cambridge rides across the parade ground during the Colonel’s Review at Horse Guards Parade in London on May 28, 2022. - The Colonel’s Review is identical to Trooping the Colour, the Queen’s annual birthday parade. (Photo by Ben Stansall / AFP) (Photo by BEN STANSALL/AFP via Getty Images)

It has already been stated that both the Duke and Duchess of Sussex and Prince Andrew will not be on the balcony with the Queen and other senior royals for the traditional flypast because they are no longer senior working members of the family.

Arrangements are currently being made for how the Queen will take part in Trooping the Colour, PEOPLE has confirmed.

Queen Elizabeth at the Chelsea Flower Show on May 23.PAUL GROVER/POOL/AFP via Getty

Britain’s Queen Elizabeth II takes a tour of the 2022 RHS Chelsea Flower Show in London on May 23, 2022. - The Chelsea flower show is held annually in the grounds of the Royal Hospital Chelsea.

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With her ongoing mobility issues, the monarch, 96, is unlikely to stand and view the troops for the entire parade as she normally does. In the last two years, she has viewed a pared-back Trooping the Colour parade in the quadrangle at Windsor Castle due to COVID-19.

She could also simply appear on the balcony at Buckingham Palace with her sonPrince Charlesto take the salute, the outlet said.

Intriguingly, up until Elizabeth became Queen, it was a rare event for a Sovereign to even visit the birthday parade.

source: people.com