The Creator descended from His heavenly plane.
Before Him, there was Chaos.
He reached into the Chaos and withdrew the twelve Elder Gods.
First came Asael the Worldmaker. The Creator gave him the power of Creation and gifted him with the first piece of the Divine Pattern. With it, he would organize Chaos and create the World. During the Beginning he is the Leader of the Elder Gods and safeguards it through the Pattern.
Second, came twin gods Zia, Scion of Light, and Ossidyx the Shadow. All the Light in creation shines from Zia, and likewise all Darkness from Ossidyx. Zia's daughter, Selis, is the moon and her son, Laron, is the sun. Because of their natures, Ossidyx and Zia can never occupy the same place in the heavens at once.
Arina, the bringer of Peace, was the next of the Elder Gods brought forth. It was she who sang to Chaos and stilled it so that the Elder Gods could could take what they needed to begin the Pattern.
The Keeper of Lore was the fifth Elder God to be born. He is aware of all that goes on in the universe and keeps meticulous track of it. The Creator gave him the second portion of the Divine Pattern. During the Time In-Between, it is the Keeper who shall lead the Elder Gods and ensure the World follows the Pattern.
Asael fashioned a Wheel the moment Ageus the Watcher was born. Ageus oversees the passage of Time by turning the Wheel. When Time began, he also had Asael fashion an unbreakable chain. Ageus bound himself to the Wheel using the chain, lest he be tempted to stop. It is said that on the last day, the chain will break of its own accord and Ageus will be free of his task.
Talmora the Lifegiver is the Elder God of Life. It was she who breathed life into the creations of her siblings, and it is she who presides over the distribution of souls.
Sorcerous Ossyra is the Elder God of Magic. She is the source of all magic, and her two sons, Hike and Veles, taught magic to mortals and the Younger Gods.
Yaar, the Wild One, became the ninth Elder God. He presides over all aspects of Nature. It was he who fashioned all the plants and animals in existence. From the smallest bird winging its way through the trees, to the largest fish in the sea.
Balest the Herald was the tenth Elder God spoken into existence. To him fall all aspects of War.
Entoma Darkwind is the Elder God of Death. Entoma knows the Fate of every mortal. It is she who ensures that souls make it to their final destination. When the End comes, she will be one of the last Gods to return to Chaos.
The youngest of the Elder Gods is Casimira. The Creator entrusted her with the final portion of the Pattern. She will lead the World to its End, for she is the Elder God of Destruction.
And so, his purpose accomplished, the Creator returned to His domain.
Working in concert, the Elder Gods took from the remaining Chaos. They sculpted mountains and valleys, flattened plains, and filled rivers and oceans. Yaar and Talmora populated the World with all manner of plants and beasts. After they had completed all this, Ageus took his place at the Wheel and Time began.
Note:This is kind of preliminary. I'd been thinking about it for a while, and this is the first time I have written it out.