The Princess Royal has been discharged from hospital, Buckingham Palace says, after a five-night stay due to minor head injuries believed to have been caused by a horse.

The palace said Anne, 73, had returned home to Gatcombe Park in southwest England and would recuperate there and return to public duty when her medical team allowed.

“I would like to extend my warmest thanks to all the team at Southmead Hospital for their care, expertise and kindness during my wife’s short stay,” her husband, Vice Admiral Sir Tim Laurence, said on Friday.

Anne, King Charles’ younger sister and the only daughter of the late Queen Elizabeth, was hurt on Sunday evening while she was walking in the grounds of her estate.

There were horses in the vicinity at the time of the incident and her medical team said her head injuries were consistent with the impact from a horse’s head or legs.

A royal source said Anne, a former Olympic equestrian, had suffered a concussion and had been unable to recall what happened.

The palace had said on Monday that she was expected to make a full recovery.

However, her upcoming engagements have been postponed and the injury meant Anne did not fly to Canada as planned this week.

—AAP