The Duchess of Cambridge presenting shamrock to the Irish Guards on St Patrick's Day, 2012.
Her Royal Highness travelled to their barracks to meet officers and soldiers of the 1st Battalion of the regiment.
Prince William is Colonel of the Irish Guards.
The royal tradition dates back to 1901, when Queen Alexandra asked for shamrocks to be presented to the newly-formed regiment.
The badge of the Irish Guards comprises a star, within which is a shamrock with three crowns on its leaves (the historic kingdoms of England, Ireland and Scotland), the shamrock being placed on a cross of St Patrick.
The centre is surrounded by a circle which bears the legend QUIS SEPARABIT - who shall separate - and the date MDCCLXXXIII (1783), the establishment of the Most Illustrious Order of St Patrick (KP).