In Greek mythology Nemesis was the daughter of Nyx the primordial goddess of the night. Nyx was born of Chaos. She gave birth to Aether alone and Hemera, Moros, Charon, Eros and the Keres with her brother, Erebus. With Dionysus, she mothered Phthonus. Apart from Nemesis, Nyx was also mother of Momus, Thanatos, Hypnos, the Hesperides, Apate, Philotes, and Geras - the Fates.
She is also said to have been as beautiful as Aphrodite and was seduced by Zeus in the form of a swan. The Goddess of Punishment, Poena, was an attendant of Nemesis.
As Nemesis/Fortuna, a conflation of the Greek deity of fate with the Roman Fortuna, she was perceived not as bringer of retribution but as having the power of changing fortune and hence she was an ideal deity to make patron goddess of gladiators. It is thought that gladiators made offerings to this 'goddess of fortune' before fighting in the Roman arenas.