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The Queen looked especially regal in London on Friday, where she headed to Wellington Barracks to mark an important royal anniversary.

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HM appropriately wore royal blue to mark a very royal anniversary. She visited the Royal Army Chaplains Department, who were granted the use of the “Royal” prefix in February 1919 by her grandfather, King George V.

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A special service honoring the anniversary was held at the Guards Chapel.

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For the occasion, the Queen sparkled in one of her wedding presents, the Carrington Feather Brooch.

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The lovely brooch features an unusual lavender-hued sapphire, and it often appears to shift colors depending on the outfit with which it is paired. Learn more about the brooch (and see close-ups!) over here!