Fortuna was the Roman goddess of fortune and luck. She was the equivalent to the Greek goddess Tyche, but while she did represent good luck, she was also responsible for bad luck, and thus was more a goddess of fate than fortune.
Fortuna's name comes from the Latin fors (the genitive of fortis) meaning 'chance' or 'luck'. Her family tree is a bit of a mystery. She was said to be the daughter of Jupiter, although there is at least one painting of her nursing a young Jupiter. Her mother remains unnamed.
She was a popular deity, and had many temples to her name, usually dedicated to a specific aspect of her influence. Sometimes her temples were paired with temples of Mater Matuta, the goddess of dawn and childbirth. Her major festival day was June 24, Midsummer's Day, known as Fors Fortuna, although she had a secondary one on June 11 in her aspect of Fortuna Virgo, 'fortune of the virgin', which she shared with Matuta. She was also considered by some to be an aspect of the Egyptian goddess Isis, and some representations of her that are obviously influenced by Egyptian religious tradition are referred to as Isis-Fortuna.
Fortuna was sometimes seen as being greatly influenced by virtus, the virtue of a person's character. A person who followed the virtues would be favored by Fortuna, and those who were not fortunate probably were not as virtuous as they appeared. However, her aspect as a goddess of fate included the idea that all things had their time, and should move from birth, through growth and achievement, and then slowly on towards death. She was sometimes represented as being veiled and blind, much as our blind justice today, indicating that she could not be swayed by our actions.
Fortuna lived on past the end of the Roman Empire, although she was not always looked upon with favor by the Catholic church. She carried on in folk mythology and art, and picked up some new imagery along the way; she was sometimes pictured with two faces, as 'two-faced Fortune', indicating she could just as easily do you harm as good. She was frequently pictured with the Wheel of Fortune (symbolizing growth, destruction, and renewal over time), a cornucopia (good fortune), a ship's rudder (as she guided fate), or a globe (which symbolized chance).