History of the Wulfen

The 13th Great Company was formed from the followers of Leman Russ from his days on Fenris, before the coming of the Emperor. As such they were known as the "Greybeards" to the rest of the Legion, while they referred to themselves as the "Wolf Brothers". Immediately preceding the Heresy, the Company was led by the Wolf Lord Bulveye.

Space Wolf legend states that the Thirteenth Company was sent by Leman Russ to pursue the survivors of the Thousand Sons, after a failed attempt to eliminate them at their homeworld of Prospero. The members of the 13th Company swore to hunt their foes down until every last one of the cursed marines was slain, no matter how long it took, nor where the traitors fled.

They vanished from Imperial records, and their loss is honoured by a black stone in the Grand Annulus (the record of Space Wolf Great Companies).

Somehow, the hardy Sons of Russ survived their journey through the Eye and emerged, long after they should have perished, in pursuit of Abaddon. Given that they vanished before the Emperor was interred on the Golden Throne, they have been missing for approximately 10,000 years.

Their reappearance at the beginning of Abaddon the Despoiler’s Thirteenth Black Crusade has brought them back into the spotlight. They appear to still be in pursuit of the goal Leman Russ set for them, and it was believed that Leman Russ himself was their leader, although this was never proven.

One other thing that sets the warriors of the 13th Company apart from the rest of their Space Wolves brethren is the large percentage of warriors who have succumbed to the animal nature that is part of the genetic legacy of their Primarch: the Mark of the Wulfen.

This genetic mutation causes their canine nature to manifest itself more fully and, amongst other things, thick hair to grow over all the body and claws to sprout from the hands. These warriors gather together in units and surrender themselves to their animalistic nature, rushing headlong at their foes, eager to use their sharp claws and teeth in close combat.

Whether the increased percentage of 13th Company Marines who have succumbed to the Mark of the Wulfen is a result of their exposure to Eye of Terror, or whether it existed before and their increased percentage in the Company is simply due to the fact that their increased stamina and strength has allowed more of them to survive than their brethren is unknown.