UK prince at Queen Mum's birthday

Charles: A history of polo accidents

LONDON, England -- The heir to the British throne, Prince Charles, attended the 101st birthday celebrations of his grandmother, the Queen Mother, hours after leaving hospital following a polo accident.

The 52-year-old Prince of Wales was knocked unconscious when he fell from his horse in a polo match Friday.

He appeared at his grandmother's side in London along with her 70-year-old daughter, Princess Margaret, who was in a wheelchair following a series of strokes.

The Prince of Wales left Cheltenham hospital in western England on Saturday morning and was driven away in a waiting car.

He smiled and waved, telling reporters: "I'm all right, thank you very much. I'm still alive."

Prince Charles spent a "comfortable night" in hospital and was given the all-clear this morning, Buckingham Palace spokesman Patrick Harrison told the Press Association.

Doctors decided he had not sustained any injuries as a result of his fall. Mr Harrison said: "He is fine and has been given the all-clear. He has no injuries as such or broken bones.

"He spent the night in a standard hospital room. It is a room rather than an open ward but it is usually used by hospital patients.

"He did not have any visitors and is expected to go to Highgrove before driving on to his grandmother's birthday celebrations."

Charles' two sons, princes William and Harry, were playing on their father's team when he was injured.

A keen horseman and polo player, Prince Charles has had a number of equestrian injuries over the years.

In June 1990 he fell during a polo match and was kicked by a horse. His right arm was broken in two places. The break did not heal properly and the arm was reset three months later.

Three years later, he was hurt again during a game of polo when he aggravated an old back injury.

In January 1998 he broke a rib after falling from his horse while fox hunting, and in January of this year, he fractured a bone in his shoulder when he fell off a horse during a hunt.

The prince also suffers from a degenerative disc at the base of his spine, which has caused some pain over the years.