Nothing completes an outfit quite like a tiara. It's a style rule rigidly adhered to by many of the world's chicest royals, including Britain's Catherine, Duchess of Cambridge, and Spain's Queen Letizia. No special occasion can be attended without a proper measure of bling atop one's head. It's just not done.
When the time comes to wear a tiara, princesses, duchesses, and queens alike head into the royal vaults to survey what their families have accumulated over generations. The royals are good at sharing; pieces pass from mother to daughter or husband to wife, and they often appear on different family members depending on the year. There are many stunning tiaras safely guarded by the ruling families of Europe, but these 10 are certainly among the most exquisite.