Fortuna
Τύχη (티케) · Roman 포르투나 (Fortuna)
Rome's goddess of fate, who spins a wheel and overturns human fortunes.
She corresponds to the Greek Tyche, but Rome worshipped her on a far grander scale.
The wheel shows it at a glance: whoever is on top will be carried down.
Medieval Europe inherited the image whole — the opening chorus of Carmina Burana sings of exactly this wheel of fortune.