Craftworlds

Craftworlds are planet-sized, self-contained starships and political entities of the Eldar (Aeldari) in the Warhammer 40,000 universe. Each craftworld functions as a living, independent world: a city-ship carrying thousands or millions of Eldar, along with their ecosystems, fleets, and a framework of institutions that govern daily life. They were formed after the Fall of the Eldar, when the birth of Slaanesh shattered their empires. To survive, exiles departed in vast, semi-biological vessels that could travel the galaxy and endure long separations from their former homeworlds.

The ships are built from and partly grown from wraithbone, a biosynthetic material that is responsive to psychic input and can house a limited form of life within. A craftworld has its own government and priesthood, led by seers (Farseers) and often an Autarch or craftworld ruler. The population includes guardians, and the warrior-caste known as Aspect Warriors, with other specialized orders. Culture and military practice vary by craftworld, and many possess distinctive customs, color schemes, and domains. Their fleets are integrated with the craftworlds themselves, and they often employ wraith constructs, including Wraithguard and Wraithlords, to augment their power.

There are several well-known craftworlds in Imperial records, such as Ulthwé, Biel-Tan, Alaitoc, Iyanden, and Saim-Hann, each with its own priorities—ranging from seer-led defense to swift raiding. Craftworlds travel the galaxy via the Webway, moving to secure worlds for settlement, safe harbors, or allies, while avoiding threats such as Tyranids and Chaos.