Just ask Crown Princess Victoria of Sweden. The heir to the Swedish throne most recently paired an ornate, 119-year-old diamond tiara with a dress from the most surprisingly accessible brand.

Princess Aiko, the only child of Emperor Naruhito and Empress Masako, finally got to wear a tiara--a borrowed one though--when she attended a ceremony Dec. 5 to her entry into adulthood.

Tiaras are a byword for royalty, and the female members of Japan’s Imperial family are no different in wearing them for special occasions. Princess ... one used by Crown Prince Akishino's ...