Kate Middleton Wears Custom Alexander McQueen for St. Patrick's Day

Today is St. Patrick's Day and the royals are celebrating. While American commoners might celebrate the holiday with some day drinking or by childishly pinching anyone not wearing green, Prince William and Kate Middleton, are ringing in the day with an important royal engagement.

The Duke and Duchess of Cambridge kicked off Sunday with a visit to the 1st Battalion Irish Guards at Cavalry Barracks in Hounslow, England. Visiting the barracks is a tradition for the royal couple, so the engagement doesn't come as a shock.

Also firmly in the "not a shock" category: Kate's amazing, head-to-toe green look. This year, the duchess opted for a bespoke, emerald green coat from Alexander McQueen, according to Kate fashion-focused Twitter account @KateMCambridge. Here's a look at full outfit:

Kate accessorized her Emerald City-worthy look with a matching hat, Gianvito Rossi black Piper suede pumps, and a chic pair of black gloves.

Here's a look at the back of the coat:

And, just because, here's one of Will admiring the back of, um, the coat:

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