The tradition may stem from multiple sources, as the conical hat shows up many times throughout fashion history. A common theory is that the hat was a symbol of being 'crowned for the day.' Before records were more dutifully kept, only kings and high nobility celebrated birthdays as they were the only ones to usually keep track of what day they had been born on. Some historians think that the idea of being a royal for a day resulted in wearing birthday crowns as time went on. Why conical, you might ask? A conical hat, known as a Hennin, was popular among court ladies in 15th century France. Portraits and scenes of court life were increasingly painted during this time as it coincided with the Renaissance which happened in the Middle Ages. The style is obvious and characterized court life for many viewers hundreds of year beyond the fashion's height.

HAPPY BIRTHDAY TO YOU. USA Today Magazine [serial online]. March 2003;131(2694):8. Available from: Academic Search Premier, Ipswich, MA. Accessed September 8, 2014.