The Creation Myth of Yhihria (Yee-heer-e-uh)

Creation of the World:
A group of ancient beings set out to create a world of their own in the universe. To do this They would create a World Engine, a wondrous device that gathered arcane, divine, and planar energies from the universe. This World Engine would collect all the energy needed to create and shape a new world. It would later be used to help the ancients ascend to godhood and watch over their new creation. Upon ascending to godhood the ancients would continue to work as parents and guardians to their fledgling world, becoming known as The Creators. After the world was finished the gods would dismantle and scatter the pieces of their Engine across the world. They would come to call the world Yhihria.
After being scattered, pieces of the World Engine would merge with the world. Some of the pieces still contained portions of the energy they once gathered. The energy radiating from these pieces would influence the shape and nature of the area around it. This could be in relation or in conflict with what the gods had done to shape it. Areas affected by the pieces would become mystical or wondrous landmarks or cradles of civilization. Some of them would even be accessed or harnessed, as energy sources, throughout history. Many of them however would be lost to time merging or being consumed by the plan, but occasionally discovered through chance or providence.
The nature of the world's creation means the original locations of the World Engine maintain a strong connection to the energies that once were gathered and channeled there. These places have especially strong infusions of arcane and divine magic. These places are known to be loci of the ley lines which spread across the world like a circulator system for magic.
However, the most notable of these are the planar energies. Yhihria has a much strong than average connection to the inner and outer planes. This connection resulted in a fusion of the material world and the planes. Some of the most notable areas even overlap with other planes creating wholly unique places in both the material world and the intersecting plane.
In the early days of Yhihria's creation the Creators walked the world and were regularly involved in shaping and protecting it. The Gods would take on and foster projects closest to their interests or domains. They tried to work together as much as possible maintaining much of the group spirit that first drew them together. As life on the planet grew the Gods would spend time shaping and influencing when and where they saw fit. After the world and it's inhabitants had been firmly established the Creators slowly backed away from the world and moved on to overseeing it from above.
The Creators would use the energy from the World Engine and their new divine powers to help shape and raise new life on the planet. Flora, fauna, species and races new and old were all brought to the planet or created from it. The new Gods looked upon their creation with delight as it slowly grew and took on a life and direction of its own. The Gods knew they could not fully control their creation and so they allowed it and its inhabitants to follow their own paths. They would guard and guide as best they could, but would not control.
Over time the Gods found they could not fully satisfy the needs of their world, despite holding all of the Divine power and domains necessary. They decided to initiate a group of Middle and Lower gods into their Pantheon. Granting them smaller domains and lesser divine power these New Gods would be taken from the world's inhabitants and were most notably the strongest and most loyal of the Creator's followers or children. These Middle and Lower gods would serve to fill out the racial, cultural, and unique natural states of Yhihria. In many ways the Middle and Lower pantheons would be closer to their worshippers and the world than the Creators.
The Creators would remain watching over Yhihria for nearly its entire existence. Very few of them died or were replaced throughout the world's history. They would act as a Council to the Middle and Lower gods as they oversaw the world and its history. The Middle and Lower pantheons would occasionally see some turn over and conflict between their ranks. The Middle and Lower gods would also remain much more invested in the world over time and would not step back as the Creators did.
The early years of Yhihria's life were filled with an overwhelming tide of magical energy left over from its creation. The Creators walked the world, in person and took the time and energy to personally shape these energies. They would use their divine power and the world's energy to shape life and bring it to the planet. Some of the Creators were intent on their creations and actively shaped every aspect. Others created seeds and allowed their creation to grow more naturally, only making adjustments and nudging them in a certain direction. All of the Creators would take inspiration from other worlds and copy beings they felt were worthy or interesting enough to bring to their own world.
In many ways Yhihria is a nexus of universal energies and influences.
The first natural born beings of Yhihria would be known as the Planeborn. The first true Yhihrians. Unlike beings, such as Genasi, who have planar parentage, the Planeborn are humanoids infused with energy from another plane. In this way they are similar to elementals in essence. These beings first came into existence from the abundance of energy and connections made to the Inner and Outer planes. They were not shaped or influenced by the Creator. They were birthed from the planet itself. They were like embers from a fire that slowly blossomed into being. Their birth was spontaneous and outside of the Creator's plans. The Planeborn were the first children of Yhihria.
As the first natural born children of the planet, the Planeborn would be adopted by the Creators and included in their plans. They would grow up alongside the other races and mingle with them creating a lineage that is nearly as old as the world itself.

Summary

The mortal races and other intelligent inhabitants of Yhihria know that the High deities, the Creators, formed the world and seeded it with life. They used their divine power to mold the world and the first beings. They inhabited the world for a time and helped to shape the first beings before leaving them to choose their own path. From this First Generation they would choose the best among them to become their stewards over the world, serving under the Creators in the heavens. 
The legend of this creation is perpetuated by records from the First Generation and those who joined the Creators as the Lower and Middle deities. Their ascension to divinity is rooted in the time the Creators walked the earth before moving on watch over it from the heavens. This provided many of the races and early civilizations time to establish themselves and be able to record these legends before they past from memory.

Historical Basis

If discovered, parts of the World Engine can point to the original plan the Ancients and Creators used to build their world.

Spread

The creation of the world is a wide spread, common legend.
Every race and religion in the world knows the legend and has accounts of it that date back to the first generation of life on the planet. This is due to the Creators themselves and their raising of those mortals who followed them to the Lower and Middle levels of divinity.

Variations & Mutation

The Creators time as the Ancients and their lives before as well as the existence or reason for the World Engine to be

Date of First Recording

Year 1 of the Creation Calendar

Date of Setting

Prior to Year 0 of the Creation Calendar