Mind you I am going to change the religion of the elves and restrict a couple of elven races while adding new ones.
The elves originate from Acenath, the island surrounded by more isles on the map. The legends say Acenath was one peninsula, united with the south-eastern continent in the past. The first elven ancestors were the known as the Sunlight Elves, or Ismer. The Ismer had what is known today as “The blood of the kings” which allowed them to control magic in any way shape or form. The Ismer well very tall elves, as tall as giants from Skyrim, to compare it easily.
They tried using their ancient magic to defeat the concept of “night” in the world, thus making the sun shine all the time. They did that, because during the day their powers grew and during the night they lowered. If there was everlasting daylight, the Ismer would become stronger and stronger, to the point of ruling the world and the other races of men. But there were some elves on Acenath that did not share the Ismer beliefs, because by eliminating the night the other races of Seraak would have waged war on the Ismer, bringing the mighty race to heel. Those elves plotted against the Ismer in order to stop the from ending the night. Their plots led to the death of Silanus, the Ismer king, now worshipped as the Sun God.
After Silanus's death, the Ismer banished those responsible for his murder and send them to the tropical island of Taharka (the larger island east of Acenath). Those elves adapted to the stormy weather, and became the Raumer – The Storm Elves. For just as the Ismer gained power on daylight, the Raumer gained power during storms. Even after Silanus's death, the Ismer continued to work on their goal of permanent daylight, and Raumer wanted revenge, as well as stopping the Ismer once and for all.
One day, there was a storm on Taharka, a storm so great that the lightning reached the ground and melted away mountains. The Raumer seized the opportunity and used their powers to enhance the storm, and bring terror to the Ismer. The storm ripped away Acenath from the other continent, and split it into many small islands, while killing dozens of Ismer. After the storm was over, the Ismer and Raumer waged war one last time, and the result was unbelieveable. All of the elves, be they Ismer or Raumer, died off with the exception of two who desired peace the whole time and hid themselves away from the tides of war. Those two were Stannis, the god of stroms, and Leylana, the goddess of Fire. From their love of one another and the love of Seraak, they gave birth to the elven race.
At least, that's what the legends say.
The descendants of Stannis were called the Ninmer, or the silver elves, now inhabiting most of Taharka. They have white skin and are as tall as the dark elves, who mind you don't exist in Seraak because I SAY SO. The Altmer are now mostly the inhabitants of Acenath, and many other races of elves were formed depending on where they migrated. For example, the Bosmer, or wood elves, had many clans occupying the south of Arken, where you see cities such as Amathea, Duwdeml, Fasnach or Wad Eyrer. SIDE NOTE TO BLITZ, the elves in your kingdom you can call them whatever you want, even dick elves, I won't get mad, as long as they worship the elven gods.
To continue the story, in Acenath the house of Iceni became the ruling house, and they used war chariots to keep all of the clans on Acenath under their heel. In Taharka, the house of Arcos slowly came to power, using foot soliders as well as mages to keep the other clans in place. They waged war with the bosmer clans of Arken, who took the Iceni as their ally. The Iceni marched on Taharka and unified the Arcos as well as the bosmer clans on Arken. However after that war was over, the men were weak and slowly recovering from the last war. And then the empire forces marched south, conquering the weakened bosmer and declaring war on the Iceni. The Iceni marched chariots on Arken soil fighting off imperial troops. There were both loses and wins, but overall the elves were too weak for another war, so they gave up the south of Arken and became a loyal client state to the Empire.
The Arcos rebellion is when the people of Taharka turned their weapons against the Iceni, killing the former king, Riendal Iceni and four of his heirs. Arcanicus Arcos earned the title - “The Butcher Usurper” due to him killing off Riendal and his children. The Sunsfly family, whom served the Iceni managed to keep the Arcos from invading Acenath, convincing them that the elves are stronger togather, rather then fighting. After that, Arcos kept trying on stealhily killing the remaining Iceni Heir, while the elves named themselves Arcosiceni, their flag being the chariot and the elven mage who rides it. The elves started colonies in the east, where surprisingly there were other elven clans as well, and came upon a plops ton of gold in the Menkauhor Desert. Soon the elves became the richest on Seraak, and, feeling stronger, they started making demands of the empire, asking for their teritory on the South back. And because the Empire refused, the Arcosiceni broke their treaties and refused to help them in the war with the Supremacy. The elves encounter a lot of internal struggle and slave decline since they started taking slaves of all races to their kingdom. The land in the east is hard to conquer, since the deserts are rich, but merciless.
That about it, what do you guys think?