Elven Migrations

The Elven Migrations was a series of migrations by the Elves over 11,000 years ago. Groups of elves would begin to move from their homeland in the western lands which was known as "Akan’nash". Many different groups of elves would start to move toward the east in different migratory patterns.

Routes
The Dune Elves would proceed to travel the vast Mîn Desert (Barrier Desert) located to the east of the homelands, which some would settle within, but many would continue on their path toward the south, and eventually into the Endless Sea and into modern day Celume Province. They would land in southern Syltör while some landed in northern Ummarnu. From there, multiple groups would split, with some Dune Elves breeding with local humans in the area which would become known as Talawa, and formed the Talawan identity. Meanwhile, ambitious elves known as the Almnutaa would migrate toward what would be known as Nunaje and settled.

The Celestial Elves would migrate away from the southern portion of their homeland, and by boat, would travel eastward across the dangerous ocean, which was plagued by storms and sea monsters. According to myth, some Lhûren landed on a mysterious island in the Endless Sea filled with monstrous creatures, which drove them out; it is thought that this island may have been Macmar. They would eventually arrive into the Lothranis Sea, which they would say to be "calm" and "heavenly", thus it's namesake, and would settle in Necua, Lingrinwë, and what would eventually become Ardol.

Not all Elves however, settled in Rathnir. Some would continue their migration toward Eldham and would become different types of peoples. Some, such as the Ice Elves, settled in a region known as Amarion, where their skin would mutate with the local tundra. There is also the Forest Elves who are native to Eldham as well. Even then, another type of elf, Uralima (Oralian or Beauridinian Elves), migrated north with the Hyakki, but chose to stay instead of continuing to Eldham, settling in Acaruñour and Ridini.

Causes
Since the the Migrational Theory has been accepted, Rathniri anthropologists and historians have proposed multiple different hypotheses for the exact trigger for the event, however the true cause remains unconfirmed.

War Theory
The War theory states that at one point, the Elves were united under one entity. However, this was not the modern definition of an empire, rather, a large confederation of different elven tribes, each with different classes and magical attenuations. At some point, a collapse occurred, causing refugees to migrate away from the region, while infighting destroyed them.

Counterarguments
However, this theory usually collides with other sources, as evidence of a possible societal collapse comes from a crystal bought back by Sareariel Lelya-Earcala, which acted as a form of memory storage for recording information. This theory is argued that they weren't under a confederation, but a large empire that ruled over multiple kingdoms of elves. Another states that invasions from another empire could of caused the groups to migrate away from the region, and that today, their lands are inhabited by a conquering people. Infighting with different groups could also be the cause.

Mutation Theory
The mutation theory suggests that all the elves that exist today, are mutated to the climate that they had adapted to. For instance, Dune Elves mutated to adapt to desert environments, and can withstand high temperatures, while being weaker to colder weather. Celestial Elves adapting their skin to temperate and jungle climates to withstand the hot jungle humidity, and the cool winters the temperate climate of the modern Celestial Highlands have.

Counterarguments
The migrations also sparked a debate on if they even were together in the first place, as the Dune Elves and Celestial Elves for instance, share no similarities in skin, biology nor any form of DNA. It is also hard to debate that they all explain different origin stories, and do not seem to mention anything about "Akan'nash" once. In fact, some explain that they weren't even from the region. The Dune Elves for instance, explain that they were always born in the desert, and were created as specs of sands, as well as many of the other Elves. The Celestial Elves believe they come from a place known as the "Great Timber Expanse", and migrated to seek their own harmonious balance.