The coronation of King Charles is set for May 6 at Westminster Abbey.

Kate Middleton's tiara for the occasion is still unknown.

Camilla will be wearing the Crown of Queen Mary.

Since marrying into the royal family, Kate has switched between three historic headpieces 13 times.

Kate's first tiara was the Cartier Halo Tiara, which she has worn 13 times.

Kate also likes the Lotus Flower Tiara and the Lover's Knot Tiara.

Kate may also wear a coronet, a small crown commonly seen at coronations.

The Lover's Knot Tiara, Princess Diana's favorite tiara, is one of Kate's go-to pieces.

Kate could wear the Grand Duchess Vladimir Tiara or the Girls of the United Kingdom and Ireland Tiara.