Crown Jewel Intrigue: Kate Middleton, Meghan Markle, Diana, Camilla and the Epic Tale of Royal Tiaras

Like little baby crowns, tiaras—which no matter how elaborate, do not fully encircle the head—also historically signify royalty, status, tradition and pageantry, and you can not only read with one on, you can eat, dance and, if you’re Princess Margaret, take a bath. 

They also really come in handy—Prince Philip‘s mother, Princess Alice, dipped into the family vault and found a tiara from which he got the diamonds for Elizabeth’s engagement ring.

The sparkling accessory even has its own day—May 24, Queen Victoria’s birthday, is International Tiara Day, dreamed up for women of all ages to treat themselves royally. And if that involves wearing a tiara, go for it.

But not all tiaras were created equally, and even if you’re royal you can’t just go checking one of the queen’s out of her vault as if it’s a library book. And you most certainly can’t wear a piece that belongs to her in the tub, even if you have been loaned it for a special event, like an Oscar nominee draped in $1 million worth of borrowed diamonds on the red carpet.