Il-Kaithe is one of the lesser-known Eldar Craftworlds. Being located close to the Eye of Terror, the Eldar of Il-Kaithe constantly wage war against the Forces of Chaos. Il-Kaithe, meaning "Knowledge of Blood," was once best known for its Bonesingers' creativity. Their talented Bonesingers are said to be able to practice their art even in the heat of battle. Since the dawn of the 41st Millennium, it has become renowned for its merciless crusades against the forces of the Dark Gods. The traditional colours of Il-Kaithe are green detailed with purple trim. The world-rune of Il-Kaithe, known as the "Helm of Eldanesh," represents the all-seeing helm the Eldar hero Eldanesh received from Asuryan himself. The Lay of the House of Eldanesh describes how the Eldar hero defeated the gods and monsters alike with the prescience that it gave him, but in the end he fell prey to his own curiosity and foresaw his own bloody demise at the hands of Khaine. The Eldar of Il-Kaithe use the world-rune depicting the helm to remind themselves that knowledge can have a terrible cost.
In the endless war against the Dark Gods, the Eldar of Il-Kaithe are a keen and vengeful blade. They are driven by a desire to scour the stars of the Great Enemy, and will ally with Commorragh and even the armies of Mankind to see their goals achieved. Their impossible quest has doomed Il-Kaithe to generations of relentless warfare – even the Craftworld’s name, translated as ‘Knowledge of Blood’, has changed meaning. Where once their title spoke of the gifts passed down through the generations and the blessings of their ancestry, in the last few millennia it has become a promise of war. Once, the Craftworld was renowned for the exquisite art of its Bonesingers. Now, these same craftsmen have turned their skills to creating only weapons, and even accompany the warhosts to battle to heal wraith-constructs and Engines of Vaul amid the crack of gunfire.
Il-Kaithe's story begins with the Fall of the Eldar -- the dying days of the Eldar empire, when the monstrous birth of Slaanesh shattered their civilisation, and the survivors fled in disarray across the stars. As one of the last Craftworlds to flee the Eldar home worlds before the Fall, its occupants saw first-hand the dark seduction and temptations of Chaos. Having barely survived the catastrophe, the Eldar of Il-Kaithe refused to despair, and so, the Craftworld vowed to seek out and eradicate the menace of the Dark Gods and their foul servants. For millennia, Il-Kaithe has continued its eternal crusade, opposing the Great Enemy at every turn, no matter the cost -- Il-Kaithe will readily ally with their dark kin from Commorragh and even with Mankind to thwart the machinations of Chaos.
- Codex: Craftworld Eldar (7th Edition) (Ebook), pg. 32
- Codex: Eldar (6th Edition), pg. 17
- Codex: Eldar (4th Edition), pg. 77