Once upon a time, a royal couple attended the St. Patrick's Day Parade, but this year was different.

The stunning Kate Middleton made her debut as Colonel of the regiment, taking over from Prince William.

William expressed his sadness at relinquishing the role but praised Kate's commitment and loyalty.

The ravishing Kate turned heads in a teal Catherine Walker coat and matching hat.

She presented sprigs of shamrock to officers and even to the Irish wolfhound regimental mascot.

The parade concluded with a royal salute, and Kate took the salute as the new Colonel.

The couple mingled with the Irish Guards Association, consisting of past members.

William drank a pint of Guinness, while Kate had a half pint, showing her refined taste.

It was a fairytale day with a surprising twist as Kate took on a new, significant role with grace and elegance.