A paramour of Alexander the Great and the heroine of a Jules Massenet opera based on the life of a fourth century Egyptian saint, this name is nothing if not dramatic. Often spelled with a diaeresis or umlaut -- aka two dots -- over the letter i, Thais is a Top 100 girls' name in France and is also popular in Spain. 

Ukrainian-American actress Taissa Farmiga bears this unusual spelling of Taisa, from Taisiya and ultimately the Greek name Thaïs.

Thaisa is a variation of the ancient Greek Thais that was used by Shakespeare for the wife of Pericles. This literary princess name is rare and attractive.