The Luna Wolves were the first Space Marine Legion to begin recruiting from another world beyond Terra. In this case, the new pool of Aspirants was found amongst the adolescent human males drawn from the violent hive city gangs inhabiting an ancient former Mining World that had devolved into a Feral World called Cthonia. Cthonia was located in one of Terra's closest neighbouring star systems in the Segmentum Solar and was within reach of spacecraft that could travel at only sublight velocities before the invention of the Warp-Drive. King Eater (Battle Barge, Unknown Class) - Flagship of First Captain Abaddon during the Manachean War. Angered and wounded that the Emperor would not accept his devotion and worship, Lorgar began what became known as the Pilgrimage of Lorgar to discover the truth of divinity in the universe. This quest ultimately culminated in Lorgar turning to the service of the Ruinous Powers of the Warp -- Dark Gods who were all too willing to accept the devotion of one of Humanity's primarchs. Before long, the Word Bearers Legion had been almost entirely corrupted by the Chaos Gods, and Lorgar and the XVII th Legion's First Chaplain Erebus were tasked by the Ruinous Powers with corrupting all of their fellow Space Marines -- starting with the greatest of them all, the Warmaster Horus.

Pacification of Schravaan (Unknown Date.M30) - This was a joint Imperial Compliance conducted by the Luna Wolves, Iron Warriors, Imperial Fists, and the Emperor's Children Legions against the xenos Badoon on the world of Schravaan. The Iron Warriors won a great victory when they stormed the final refuge of the Badoon. They breached the defences and held while the other Legions carried the city beyond. During the following victory feast, Horus proclaimed Perturabo the greatest master of siege warfare in the Great Crusade. Fulgrim, the primarch of the Emperor's Children then inquired to his brother Dorn whether he thought even the defences of the Imperial Palace could resist the Iron Warriors, in which Dorn replied that he regarded the defences as being proof against any assault if well-planned. Perturabo flew into a rage and unleashed unfounded accusations against his brother. After this the two rarely spoke, and neither Legion would serve again in the same campaign for the remainder of the Great Crusade. The overriding belief that animated the Astartes of the XVI th Legion prior to Horus' demise was in the ultimate superiority of Horus and themselves over all other beings in the galaxy. In continually seeking to prove themselves as the greatest of the Space Marine Legions, they did indeed achieve more than their fellow Astartes in terms of the sheer numbers of worlds brought into the Imperial fold prior to the Heresy. Beneath these non-commissioned officers were the rank-and-file Battle-Brothers of the Luna Wolves and the Sons of Horus. This simple hierarchy belied the truth of matters when applied in practice within the XVI th Legion. Within each rank, prestige and personal reputation counted for much within the brotherhood of Space Marines. One avatar of the increasing influence of the Legion's Cthonian brothers was the late reemergence of Cthonian gang-sigils graven into a given Space Marine's armour that recorded his notable kills and deeds, as well as to which company of the Legion they belonged. This was a practice which accelerated rapidly after the XVI th Legion had transitioned into its new identity as the Sons of Horus following the elevation of Horus to the rank of Warmaster.

The Horus Heresy

Lorgar and his Word Bearers originally came from Colchis, a world defined by religious fanaticism. They had long worshiped the Emperor as a god. The Word Bearers had sought to spread their Cult of the Emperor to every world they added to the Imperium. But the Emperor deeply disliked and mistrusted organised human religion, blaming it for much of the darkness that had plagued humanity's history. Guljuk Ygethddon - Sergeant Ygethddon commanded a Despoiler Squad of the 9 th Battle Company, 2 nd Battalion. The Dark Gods portrayed themselves as victims of the Emperor's psychic might, and claimed falsely that they had no real interest in the happenings of the material world. Magnus the Red, the sorcerous primarch of the Thousand Sons Legion, had also travelled into the Warp via sorcery to try and stop Horus from turning to Chaos. Magnus explained that the Warmaster's vision was only one among many possible futures, but one that Horus alone could prevent. Those captains of the Luna Wolves (and the Sons of Horus after the Legion's name change) who were chosen to serve in the Mournival were generally considered the best officers of the Legion by their fellow Battle-Brothers. In general, each of the four members of the Mournival were chosen because they each possessed very different personalities and characteristics that were intended to complement one another and provide the Warmaster with a wide array of different viewpoints.

The origins of the Mournival are uncertain as the tradition either began soon after Horus was installed as the leader of the Luna Wolves Legion when the Great Crusade reached his homeworld of Cthonia or was an outgrowth of the informal warrior lodges that began within the Legion after their conquest of the world of Davin only 60 years before the start of the Horus Heresy. Taking into account likely losses from the ground war that followed the virus-bombing of Isstvan III, and elements of the Sons of Horus Legion not in the Isstvan System at the time, it would follow that Horus began his war of betrayal with around 70,000-110,000 Space Marines of his own Legion at his disposal, with considerable evidence present in Imperial records that the latter figure is the more accurate. However there is some conjecture amongst Imperial savants that Cthonia was destroyed deliberately by the Imperium following the end of the Horus Heresy, when the Loyalist Astartes Legions moved to purge the homeworlds of each of the Traitor Legions during the Great Scouring to remove their Chaos corruption.Abaddon also concludes that Epimetheus can't be his "erstwhile brother," as he personally saw that Grand Master dead. However, as Loken rejected membership to the Grey Knights, Abaddon was most likely referring to Severian (who became the Grey Knight Grandmaster known as "Iapto"), an old rival from the time of the Luna Wolves. [9] Wargear Serghar Targost - Captain of the 7 th Company and the Lodge Master of the Sons of Horus' warrior lodge, the heart of the Legion's growing allegiance to the Chaos Gods. The Triumph at Ullanor, an ancient mural portraying the gathering of the brother-primarchs at the Triumph of Ullanor; from left-to-right: Sanguinius, Mortarion, Magnus, Angron, Jaghatai Khan, Lorgar, Rogal Dorn, Horus and Fulgrim Oblivion (Strike Cruiser, Unknown Class) - The Oblivion was severely damaged during Abaddon’s assault on Manachea Vysidae during the Manachean War. It is believed that the Oblivion was amongst the first vessels to be repaired at the recently conquered facilities of Port Maw.

Tactical Squads made up half this strength numerically, with the Legion placing in general great importance on the use of Tactical Squads in every deployment. The rest consisted of two veteran units, three reconnaissance units, a heavy support squad and multiple batteries of support weaponry. In eschewing formality and fixed structure above the basic level of the company, Horus demonstrated his pragmatism and his preference for waging war with careful precision. Within the Luna Wolves and the later Sons of Horus, squads also commonly had their own honorific or epithetic titles rather than simple numerations: the Illuminators Prime, Death Makers, Jerrok's Reavers, the First Sons, and similar appellations, while some were named for the Sergeant or Chieftain that led them if their leader's own reputation was strong enough alone.

The following information is not to be regarded as officially sanctioned and/ or is not written from an in-universe point of view. A detailed explanation of the term "Trivia" as used in the Lexicanum can be found here.