The Dyzanique was a secretive techno-esoteric cult located in the Sol System, whose fealty to the Emperor predated his alliance with Mars. Aboard the Iliastus Satellite, that served as their base of operations, they developed new weapons for the Imperium's use during The Great Crusade and had begun field testing their latest weapon, the Iliastus Pattern Assault Cannon, when the Horus Heresy began.[1]
Source
- 1: The Horus Heresy Book Three - Extermination, pg. 267