"Trust not in their appearance for the Eldar are as utterly alien to good, honest men as the vile Tyranids and savage Orks. They are capricious and fickle, attacking without cause or warning. There is no understanding them for there is nothing to understand -- they are a random force in the universe." —Imperial Commander Abriel Hum

The Eldar, or Aeldari as they were known in the Eldar Lexicon before the fall of their lost realm, or the Asuryani (followers of Asuryan) as they refer to themselves, are an ancient humanoid alien race whose vast empire once extended the width and breadth of the known galaxy. The Aeldari Empire was without equal, and they counted themselves masters of the stars. But millennia ago, the Aeldari's overweening pride and their fall into hedonistic practices led to a cataclysm that all but eradicated their kind and led to the birth of the Chaos God Slaanesh. Despite their boundless power, the heart of their civilisation was torn out by this catastrophe of their own making, forcing the surviving Aeldari, now calling themselves "Eldar," to flee upon gigantic, continent-size starships called Craftworlds. Now they cling to survival by a thread, fighting the horrors of the galaxy with ritualised discipline and consummate skill.

The Eldar race has a long and complex spacefaring history, so long in fact that little is known for certain about the course of their physical evolution and early planet-bound existence. The original Eldar homeworld was destroyed during the catastrophic collapse of the Eldar civilisation known as the Fall of the Eldar. The remnants of Eldar culture that survived the cataclysm preserved much of their species' history in the form of traditional stories, songs and dance. Written records, monuments and visual records were almost completely destroyed except for a few instances where they were taken aboard voidcraft fleeing from the doomed worlds.

Over a million standard years ago, the Eldar alone ruled the stars as the undisputed masters of their own destiny. Such a position was their right, they thought, and their preeminence was beyond doubt. In many ways, the Eldar had good reason for such hubris, for no other race had posed a serious threat to their wealth and stability for time immemorial. They were convinced that they no longer had anything to fear from the galaxy at large, and they may have been right, but the real danger came from within. The doom of the Eldar, when it came, took a form far more subtle and dangerous than that of alien invasion. At that point in Eldar history, nothing was beyond their reach and nothing was forbidden. The ancient race continued their glorious existence unaware or unwilling to acknowledge the dark fate that awaited them. They plied the stars at will, experiencing the wonders of the galaxy and immersing themselves completely in the endless sensations that it offered them. Such was the technological mastery of the Eldar that worlds were created specifically for their pleasure, and stars lived or died at their whim.

As a humanoid race, Eldar are physically similar to humans, although not entirely identical by any means. They possess longer and cleaner limbs, and fine ascetic features with penetrating and slightly slanted, almond-shaped eyes. Their ears are also slightly pointed, but otherwise they could pass as human at first glance. The most obvious difference between humans and Eldar can only be seen when they move, for the movements of an Eldar radiate a subtle grace which is impossible for a human to emulate. This can be seen in even their slightest gestures or the dexterity with which they manipulate small objects.