The Race of the Alva'a/Elves
The race of Alva'a, known in the Human tongue as Elves, were formed contemporarily, or nearly so, with humans in 30,000 BT, a race known as much for their ethereal beauty and grace as for their affinity for the arcane; the more high-minded Elves who are aware of history sometimes uphold the idea that the Gods themselves assisted with the creation of the first of the Alva'a rather than just being formed by the hands of the lesser Angeli, though such a claim is based on history that stretches so far back that very few of even the Elvenkind have been taught such things. Elves formed great and wondrous civilizations in parallel with their Human counterparts for millennia, with almost entirely peaceable relations between the two; although intermixture of their cultures was rare enough for the two to generally regard one another's denizens as exotic, there were no real conflicts large enough to be of any particular note. It should be noted that the Alva'a were among the most steadfast compatriots of Humans in their earliest conflicts with Daemons, though. Brithín'le Alatáni Elex'jalín, the High Queen of the Alva'a at the time (Elex'jalín being an Alva'an title often translated as "Starry Queen" from elex, "astral" and jalín, "queen"; "High Queen" does not entirely capture the term in translation, as it is typically regarded as having shades of spiritual significance, but it is the most common translation) was a noted ally of Mikhalux and his family. The first shades of unrest among the Alva'a began to crop up with the First Terran Crusade, when a notably-sized subset of Elvenkind began to worry that their race had been weakened by their prolonged reliance upon Humanity; the Alva'a joined humanity's efforts to repel the demons, but many did so with a sense of wariness about the consequences of such prolonged association with their Human allies by the time of the Second Crusade, worried that once the demon threat was ended, they would fall under Human control. This all came to a head in 0 AT, when roughly half of all the Alva'a submitted to the Empire, and roughly half clung fiercely and defiantly to the Old Ways. A dire magical event known as Mirjaxale'í, "the Sundering", resulted from the clashes between immensely powerful Elf mages on both sides and these two factions were split into two entirely separate races of Elves, Sarluun Alva'a, Wild Elves, and Briján Alva'a, the High Elves. Almost immediately, a kind of bloody 'civil war' broke out. At a higher cost in blood and strife than they might have initially guessed, the combined forces of the High Elves and the Empire managed to force the Wild Elves to negotiate, and a compromise was reached to avoid further loss of life on all sides. All of the cities of the Alva'a of old would fall to the High Elves of the Empire. In exchange, the Wild Elves of Terra could live self-governed on certain fringes of the Empire and beyond and preserve the pure, unsullied Old Ways of Alva'a as they saw fit. A few clans of Sarluun were unwilling to make such a sacrifice to preserve the Old Ways and joined the Empire. Others assimilated into the non-Empire societies they encountered beyond the Empire's borders, such as the Isle of Artana. But the rest were so committed to the Old Ways that they accepted their Exile with pride and made their own way in the wildwoods of Terra. Twelve millennia passed; the lingering bitter taste of the Sundering left in the mouths of both sides leave some High Elves to view the Wild Elves as savages and some Wild Elves, in turn, to view their counterparts as traitors. But in truth, the races are generally indifferent to one another, as contact between them is mostly uncommon nowadays.
Still won't be as bad as the Space Wolves are stereotyped as though. That an in lore explanation why they have so much wolf everything is because they are constantly hunting wolf so wolf is their primary source of clothing besides imports but wolf fur and leather makes sense because these wolf lands are very cold. 
