As King Charles and Kate Middleton receive cancer treatment, another health scare has the royal family operating below full strength

Princess Anne’s hospitalization following an “incident” at her home is the latest setback for the British royal family.

Royal, 73, is unable to continue with her planned schedule this week after she sustained a concussion and minor injuries on the estate of Gatcombe Park on June 23, for which she remains hospitalized. Due to the concussion Princess Anne sustained, the exact details of the accident are unable to be ascertained, although her injuries are consistent with a potential impact from a horse’s head or legs. The Telegraph reported that King Charles’ sister has suffered memory loss, believed to be temporary.

In the wake of the incident, a spokesperson for the palace said that Princess Anne will not be able to attend the state banquet held in honor of the Japanese state visit to the U.K. on June 25. The royal is a regular presence at the events, including attending the most recent state banquet when South Korea’s President Yoon Suk Yeol visited the U.K. in November 2023.

Queen Elizabeth’s only daughter also had plans to visit Canada this week but will not be able to fly, per medical advice.

A Buckingham Palace spokesperson said on June 24, “Her Royal Highness sends her apologies to any who may be inconvenienced or disappointed as a result.”

The Princess Royal’s hospitalization puts the family’s “hardest-working” member on the sidelines. She is known for her strong work ethic and often records the highest number of annual royal outings on behalf of the monarch, reportedly clocking 457 engagements in 2023 — even more than King Charles’ official count.

“She just gets on with it, often carrying out multiple engagements in one day,” Queen Elizabeth’s former press spokesman Dickie Arbiter told The Telegraph of Princess Anne’s dedication.

“Of course, much of what the King does is behind the scenes, in meetings and going through his red boxes, which doesn’t warrant a mention in the Court Circular,” he added about King Charles.

Though the palace said that Princess Anne has been hospitalized as a “precautionary measure” and is “expected to make a full and swift recovery,” the incident marks the latest blow for the British royal family in light of King Charles and Kate Middleton’s recent health shocks.

On Feb. 5, the palace announced that the King was diagnosed with cancer and would postpone public-facing duties amid his treatment. Weeks later, on March 22, Princess Kate announced that she has cancer and is undergoing chemotherapy.

The diagnoses marked the first time that two senior working members of the British royal family simultaneously had cancer, leaving Queen Camilla and Prince William to step up as the faces of the monarchy. Princess Anne, Prince Edward and Sophie, the Duchess of Edinburgh also continued with a full royal workload.

King Charles, 75, resumed forward-facing royal work in late April, and Princess Kate, 42, attended Trooping the Colour on June 15. The Princess of Wales’ presence at the event was highly significant as her first public appearance in nearly six months. However, palace aides emphasized the moment didn’t mean Princess Kate was resuming royal duties. Any outings in the near future will be based on when she feels able and under the guidance of her medical team.

“She has been doing what’s right for her and recovering privately at home. She is dealing with it the best she can,” a source close to the royal household tells PEOPLE exclusively in the latest cover story.

“The monarchy is going through one of the most difficult sets of challenges,” adds Ailsa Anderson, a former press secretary to Queen Elizabeth.