The craftworld of Ulthwé is a highly militaristic craftworld. Its people have long been accustomed to warfare, for Ulthwé is situated perilously close to the Eye of Terror - the warped part of the galaxy which is the stronghold of Chaos.

Ulthwé is known amongst the craftworlds for the many Eldar there who follow the Path of the Seer and the Path of the Warlock, possibly due to the craftworld's proximity to the Chaos shrouded Eye of Terror. The Ulthwé need their numerous Farseers to keep watch for the many and varied guises of Chaos but those from other craftworlds often hint that it is the Eye of Terror itself which has tainted the inhabitants of Ulthwé and exaggerated their psychic potential.

Constant warfare has hardened its people, not just the Aspect Warriors, but all of Ulthwéan society. The need for vigilance in the face of their greatest enemy has led to the creation of a standing force of Guardians known as the Black Guardians of Ulthwé, after the colour of their uniforms. Thanks to this large force of permanently mobilised troops the craftworld of Ulthwé has endured constant warfare for hundreds of years.

Ulthwe means the 'Song of Ulthanash' and its symbol is the Eye of Isha. This represents the tears shed by the goddess Isha for her mortal children the Eldar. The colour of Ulthwé is black, the Eldar colour of mourning, and it is usual for Eldar to wear this colour. Vehicles are also likely to be coloured black, with bright overlaying camouflage in bone or red.