Mnemosyne

Mnemosyne was the personification of memory. A Titanide or Titaness, she was a daughter of Uranus and Gaia and the mother of the nine Muses by Zeus: In Hesiod's Theogony, kings and poets receive their powers of authoritative speech from their possession of Mnemosyne and their special relationship with the Muses.
 * Calliope
 * Clio
 * Erato
 * Euterpe
 * Melpomene
 * Polyhymnia
 * Terpsichore
 * Thalia
 * Urania

Zeus and Mnemosyne slept together for nine consecutive nights, thus birthing the nine Muses. Mnemosyne presided over a pool in Hades, counterpart to the river Lethe, according to a series of 4th century BC Greek funerary inscriptions. Dead souls drank from Lethe so they would not remember their past lives when reincarnated. Initiates were encouraged to drink from the river Mnemosyne when they died, instead of Lethe.

In Roman mythology, Mnemosyne's equivalent was Moneta.