Heavy is the head that wears the crown? Ask Kate Middleton .

The Princess of Wales wore her biggest tiara to date during a state banquet at Windsor Castle Dec. 3, stepping out in a massive, diamond-studded accessory that has not been publicly worn in 20 years.

Joined by husband Prince William , Kate sparkled in Queen Victoria's Oriental Circlet Tiara, a Garrard & Co. headpiece commissioned by Prince Albert in 1853 to incorporate 2,600 diamonds set in gold.

The 43-year-old paired the royally luxe diadem with a sparkling blue Jenny Packham gown. For accessories, she wore diamond earrings that belonged to Queen Elizabeth the Queen Mother as well as the Royal Family Order sash and the Royal Victorian Order star.

And Kate's tiara has quite the story to it. After all, it was or

See Full Page