A snippet from the origin myths, according to the Westron tradition:
Serpent Earth coiled herself to sleep after the Long Night in which all things came to be. The black sun Syr grew ever larger until it threatened to overcome the gold sun Hael. In time they struggled, as Serpent Earth slept on. The Three Women, who are the mothers Tael and Luin (mothers of all man) and Masiel (mother of the Kaladri), were wary that the two suns would wake Serpent Earth who would destroy her children in her wrath. They made a peace between them where Syr would have the night and Hael the day. In so doing the Three Women were lifted from Serpent Earth to watch over the men and became the grey and red moons, with Masiel as the black moon to keep the peace between the suns.
Now that night and day kept the great gods at peace, and Serpent Earth slept, the spirit gods made their way among man and the moons watched over all.
Until Serpent Earth wakes and destroys the world.
You can read a little more on the Westron creation myth in my earlier post The World: A Bedtime Story.