When Kate Middleton married Prince William in 2011, the world wondered if she might wear the Spencer Tiara like Princess Diana did on her wedding day. Instead, the new Duchess of Cambridge made her tiara debut in a diamond piece borrowed from Queen Elizabeth, the Cartier Halo Tiara.
Since then, Kate has worn just four other tiaras in her nearly 15-year royal career, mostly favoring one of Diana's go-to headpieces, Queen Mary's Lover's Knot. Although the Princess of Wales frequently reaches for the diamond-and-pearl design—the royal has worn it a whopping 13 times—she's also pulled off some major tiara surprises over the years.
