Princess Anne is in hospital after suffering minor injuries to her head and a concussion after it is believed she was kicked by a horse on her Gatcombe Park estate.
The Princess Royal, 73, an Olympic-medal-winning horsewoman, was walking on her Gloucestershire estate on Sunday evening when the incident happened.
Emergency services were despatched to the estate and, after medical care at the scene, the princess was transferred to Southmead Hospital in Bristol for appropriate tests, treatment and observation.
Buckingham Palace said in a statement: “The Princess Royal has sustained minor injuries and concussion following an incident on the Gatcombe Park estate yesterday evening.
“Her Royal Highness remains in Southmead Hospital, Bristol, as a precautionary measure for observation and is expected to make a full and swift recovery.
“The King has been kept closely informed and joins the whole royal family in sending his fondest love and well-wishes to the princess for a speedy recovery.”
It is understood the princess was walking within the protected perimeter of Gatcombe Park when the incident occurred.
The exact cause of the injuries is unconfirmed, but Anne’s medical team have said that her head injuries were consistent with a potential impact from a horse’s head or legs.
Emergency services were dispatched to the estate and the princess received medical care at the scene.
She was transferred to a hospital for tests, treatment and observation, and was accompanied by her husband Vice Admiral Tim Laurence.
Anne will now miss several engagements this week, including the state banquet for the Japanese State Visit on Tuesday and a visit to Canada.
A Palace spokesman said: “On doctors’ advice, Her Royal Highness’s engagements for the week ahead will be postponed. Her Royal Highness sends her apologies to any who may be inconvenienced or disappointed as a result.
“The Japanese State Visit will go ahead as planned, though sadly Her Royal Highness will be unable to attend the State banquet tomorrow.”
Princess Anne is famed for her love of horses and was the first member of the Royal Family to ever participate in the Olympic Games back in 1976, taking part in the three-day equestrian event.
The princess was further praised for her riding skills earlier this month when her horse was spooked at Trooping the Colour.
She was able to get the jittery horse back under control without disrupting the parade.
The Princess Royal was riding beside Prince William and Prince Edward at the time of the incident, and Edward can be seen in footage of the incident turning around after realising there was a problem with her horse Noble.
Zara Tindall said that the princess remains a keen equestrian decades after her Olympic appearance in Montreal, Canada.
“Our horses are in our family, so there’s always discussions about performances and things like that,” she told PEOPLE last year.
“There’s horses in her life, and she does a bit of breeding as well. So there’s always horse conversation going on.”