The Irish Guards' regimental mascot, Conmeal the Irish wolfhound, was given his own sprig of shamrock by the Duchess of Cambridge.
The St Patrick's Day tradition dates back to 1901.
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An exclusive poll of the capital's residents for ITV London has found Labour would make sweeping gains if an election were held tomorrow.
Research into property prices has found London has more areas with an average price of more than £1m than anywhere else in the UK.
A permanent memorial will be unveiled today in memory of murdered Middleton soldier Lee Rigby.