LONDON — Britain’s Princess Anne was hospitalized with a concussion and minor head injuries but was expected to make a full recovery, Buckingham Palace said Monday, after an incident that appeared to have involved a horse.

       While the exact cause of the injuries was uncertain, a palace official said that Anne — King Charles III’s sister and Queen Elizabeth II’s only daughter — had been walking Sunday in an area of her Gatcombe Park estate where there were horses and that the injuries were consistent with an impact from a horse’s head or legs.