The Avenians were Humans who resided on Ark Reach Secundus during the Great Crusade. Mechanicum geneticists recorded that the Avenians possessed an incredibly diverse genetic baseline noted to be far removed from the archetypal human genome. It was speculated this was due to the millennia of separation from the rest of humanity during Old Night.
The Avenians were described as being graceful and fine-boned with facial features sharp and angular. Although they appeared to be weak and fragile; later research proved their bodies to actually be flexible and strong.
They lived in silver towers on top of the tallest mountain peaks of Heliosa. These towers were interconnected by feather-light bridges.The Avenians were also noted to have a close relationship with a wide variety of aerial beasts.
Avenian Forces were noted to employ snow-shrikes, razor beaked birds, to break Imperial forces during their assaults. The Avenians were also know to actually ride on the backs of larger animals.
The Avenian government was comprised of a polyarchal leadership headed by what was known as the Phoenix Court. Negotiations between the Imperium of Man and the Avenians were unsuccessful and resulted in a war of compliance.
Defense of Heliosa
The Thousand Sons recorded over 3 million defenders being killed in the 6 month campaign of compliance.