Prince Charles as a young man playing Polo on Smith's Lawn in Windsor Great Park.
The Prince of Wales became interested in polo as a child, watching his father, The Duke of Edinburgh, play at Windsor.
His Royal Highness played in all four positions, but usually at No 4 (back).
Although Polo was played in ancient Persia, the modern game of polo is said to come from India, where the game was probably known as Pulu.
Two British soldiers in India helped set-up the Calcutta Polo Club, in 1862.
Military officers then imported the game to Britain and the British are subsequently credited with spreading polo worldwide, in the late 19th and early 20th century.