The Duchess of Cambridge was the guest of honour for the 1st Battalion Irish Guards' St Patrick's Day parade.
The soldiers came out in full ceremonial uniform at Mons Barracks in Aldershot.
But it was a little too much for one guard who collapsed minutes before the royal arrival.
The Duchess was presented with a shamrock before she began distributing them to 40 Officers and Warrant Officers.
She also honoured the regimental mascot, Conmeal, an Irish Wolfhound.
The Irish Guards' tradition of handing out fresh sprigs of shamrock dates back to 1901. Every member of the regiment - even those serving in Afghanistan - will get a shamrock at some point today.
This was the Duchess of Cambridge's first solo military engagement and will be the start of a long-standing relationship with the Irish Guards.