Kate Middleton's Gold Shamrock Brooch Has a Rich History with the Royal Family

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The royals are nothing if not traditional. And this morning, in honor of St. Patrick's Day, the Princess of Wales is participating in the century-old custom of presenting shamrocks to the Irish Guards.

Naturally, Kate opted to adorn her coat with a holiday-appropriate brooch. Read on for the shamrock pin's rich royal history.

The brooch is unique, as it reportedly isn't owned by someone in the royal family.

The Princess of Wales has an extensive personal jewelry collection, some of which she inherited from Princess Diana; she's also been known to borrow pieces from the Queen. But the shamrock brooch reportedly belongs to the Irish Guards.

Per Lauren Kiehna, who runs the site the Court Jeweller, the brooch "is loaned out to royal ladies who are associated with the regiment."

Despite being a popular piece of jewelry associated with the royal family, its origin story is still somewhat unclear. Some reporters cite Queen Alexandra as the first owner of the brooch, but according to Up the Micks! An Illustrated History of the Irish Guards, a book written by James Wilson, which features a foreword by the Duke of Cambridge, the piece was crafted by Cartier and then presented to Princess Mary, the Princess Royal, by the regiment in 1961.

Wilson writes that when Princess Mary died, the brooch was purchased by the regiment at an auction of her personal jewelry. It was then worn by the Queen Mother.

Following the Queen Mother's death in 2002, Princess Anne was seen wearing the pin at events related to the Irish Guard.

Kate, the Princess off Wales wore the brooch for the first time in 2011, and she has been the exclusive public wearer of the piece ever since.

She debuted the shamrock brooch at the Victoria Barracks in June of 2011, during a presentation of service medals.

More recently, Kate has been seen wearing the pin at the annual presentation of shamrocks, a St. Patrick's Day tradition started by Queen Alexandra in 1901.

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