In their initial conception, crowns were used to indicate beings who were believed to be ordained by the gods. While the crown style changed from feathered headdresses, to gold circlets, the importance did not. The actual word “tiara” originated from Ancient Persia, where a tall and richly ornamented tiara was made for the king's wear. It stayed securely on the king's head as it was tied together in the back, and was typically covered in jewels and gold embellishments.
The royal tradition of wearing a tiara later spread to Ancient Greece after Alexander the Great assumed complete authority. Despite the fact that most of Greece accepted the wearing of diadems in their hair, the Romans still rejected the idea and continued to wear laurel wreaths instead. Even Julius Caesar refused the offer of a heavily laden crown after his triumph over Pompey. It wasn't until the entire annihilation of the Roman Empire that the tiara was viewed uniformly as a symbol of royal authority.
The next type of crown was later found in Medieval Europe. Rather than a diadem in which you tied together, the European kings wore circlets, or coronets, upon their heads. The first known of this type was believed to have been made from one of the nails from the Cross, and was loaded with precious stones and gold.
[1weddingsource.com/dresses/bridal-accessories-bridal-tiara.php]
http://www.johnnydepp-zone.com/boards/viewtopic.php?t=47481
