Harry, 17, finished unhurt but muddy

Harry played in the Lines position, the Wall Game equivalent of a flanker.

He was said to have enjoyed the game, finishing extremely muddy but uninjured.

A spokesman for St James's Palace said: "Harry emerged with no injuries and very much enjoyed himself.

"He played well, he played on the outside, not in the middle where all the scrumming takes place.

"He was doing a lot of kicking and it was a good match, the ball came into loose play more often than usual, so it was a very exciting game."

The teenager was selected to play for the Oppidans, the non-scholars team, to take on the Collegers, or the scholars.

Many old Etonians have admitted to being baffled by the rules of the Wall Game, which is one of the oldest forms of football in existence.

No score

Two teams of 10 battle it out along a 118-yard long wall, which divides Eton's playing fields from Slough Road.

The pitch is only five yards wide and runs the length of the wall, with goals at either end.

Play features a series of scrums to try to gain control of the ball and "sneaking", "furking" and "knuckling" are banned.

Players are allowed to push other players' faces into the red brick wall, but are not allowed to twist their hands while doing it, as that would be knuckling.

Furking involves passing the ball back and sneaking is the Wall Game equivalent of offside.