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Origins

The Black Thorns are an old chapter of the Sons of Dorn, believed to be from the Fourth Founding and created from the gene-seed of either the Fists Exemplar or the Excoriators. They are a crusading chapter, though not much like their cousins the Black Templars; they are merciless and unprincipled, delivering excessive force to their targets and ignoring all damage they make take in the process.

They were founded in Segmentum Pacificus, their first patrol being within the Nova Terra sector. This proved influential on them in the Nova Terra Interregnum, when they returned in the heart of the forces putting down the rebellion. They have, more than most astartes, spent their existence fighting humanity, for the good of humanity. This has made them hard men - if they ever were otherwise - but has not lessened their resolve or pulled them over the cliff of Chaos, though many teeter on the cliff's edge of Khorne, in their younger centuries.

Homeworld

The Black Thorns have always been fleet-based, recruiting eclecting from the sectors they operated in for their first two milennia. During the Nova Terra Interregnum, they developed the habit of recruiting from the sons of those they fought. After it, they continued this habit; they had developed strong ties with the local Ordo Malleus that ensured they were well-supplied with battles against human foes, and well-protected from questioning about the possibility of Chaos taint from the foes passing to their progeny. They do not, however, recruit the children of specifically Khornate cults; they recognize their susceptibility to the unholy blood hatred and choose not to risk amplifying it.

Beliefs

Like their ultimate progenitors the Imperial Fists, they believe in the purifying, clarifying power of pain, refusing sedatives and analgesics regardless of circumstance, and are known to employ the pain glove when they either have fallen short of their obligations or simply need to make difficult decisions outside the immediate context of war. Another peculiarity grew from their war against the Nova Terra Ur-Council; they preferentially take their recruits not from the worlds they protect, but those that they attack. If a city marches against the Thorns, they will kill its fathers and induct its sons.

Like most chapters, they don't believe the Emperor is a god. They do, however, have nearly-religious faith in the importance of human unity. For this reason, they hold no relics of the Great Crusade or Horus Heresy, but have two dozen suits of armor and a handful of weapons from the Terran Unification era. The Chapter Master's sidearm is a disintegrator pistol used by the first Legion Master of the Seventh Legion during the Siege of Roma (where the Seventh earned its first battle-honor), the Master of the Forge has custody of a relic Volkite Caliver, and the Lord Executioner (Captain of the 1st Company) has a Plasma Burner supposedly wielded in the first ever combat deployment of astartes.

It's well known within the chapter that at a certain age, usually around five centuries, astartes undergo a certain change. Before this point, they are bloodthirsty, and their training focuses on channeling that thirst, and warding them away from the path of the Khornate heretic. A chapter secret, concealed (though poorly) even from the younger brothers is that all those who have experienced the change before their seventh century did so immediately following a dangerous brush with the worship of the blood god, and that this change is the result of a Thorn who sees what he could become and emphatically steps away. Left unsaid is how many have had this brush and succumbed; not because it is high enough to shock, but because it is low enough to give younger Thorns misplaced confidence. In their seven millennia, they have had some nine thousand astartes names entered into their records; of these, five thousand have felt the temptation to Khorne at least once in their life. Only one hundred and thirty-two of those fell. However, careful reconstruction has concluded that only ninety-seven felt this temptation on two occasions with a period of wellness in between them; of these, ninety-six fell, making up over two-thirds of the total. They have concluded, therefore, that believing oneself to be past the danger, or stronger than it, is itself very dangerous. No astartes is permitted to rise above the rank of lieutenant, and few above sergeant, until he has overcome this test. Specialist ranks apply the same standard, giving no command authority to those who have not 'tamed the thrill', with the exception that Chaplains may not even begin their specialist training before they have accomplished their taming.

Those records are maintained entirely by serfs, not Librarians. The Black Thorn chapter believe that writing down knowledge profanes both knowledge and knower, and therefore commit all valuable knowledge to memory. As a concession to practicality, serfs are allowed to question the battle-brothers about their knowledge with the expectation that they will proceed to write it down. While most brothers know how to read, the accepted procedure for learning of the record's contents is to call a serf-scribe and ask them to fetch the knowledge, which they will do either by consulting their fellow scribes who know it, or by reading the records, and will then return with an oral recitation of the facts requested; this maintains the conceit that they have not necessarily profaned the knowledge. Mathematics is a considered a special exception, as in the view of the Thorns it is knowledge which is inherently textual in nature and therefore cannot be profaned in this way, an exception which is surely a relief to the Techmarines and quartermasters of the chapter.

Combat Doctrine

The Black Thorns practice total warfare in the most extreme sense. The younger brothers of the chapter are an unflappable battering ram, charging through the battlespace, destroying every man and obstacle in their path. They do not exclusively resort to melee; their Scouts are hard to discourage from switching from pure surveillance to sniping, but except when enemies close with them unexpectedly, can easily be discouraged from close combat. But their fully-implanted battle-brothers are moved to the Assault specialty before Devastators, as the charge and the forward momentum of the offensive is in their blood.

Older Thorns, who are generally responsible for strategic doctrine, gain temperance, but keep their ruthlessness. A Thorns campaign will not hesitate to destroy large portions of a Hive if most of its population is in rebellion. Leadership which did not rise in counter-rebellion, even that which stood by idly, will be mercilessly killed, with the only ones spared being children who the chapter chooses to take as initiates or serfs. A Black Thorns campaign will leave just enough survivors to carry on the memory of what happens to those who defy the Righteous Imperium of Man.

In terms of armament, power swords and force swords are preferred over other close combat weapons, and lightning claws are especially disliked. Low-grade psychic talent, insufficient to manifest any powers but enough to wield force weapons, is abnormally common in the chapter, though Librarian-grade psykers are less common than normal. It's rumored that Black Templars recruits who display psychic abilities quietly banish them to the Thorns, though no evidence for this claim has ever been demonstrated. In ranged weaponry, they have a mild preference for lascannons and other powerful but slow weaponry over less powerful weapons with higher rate of fire like the heavy bolter. These tends to makes them excellent at destroying enemy armor and fortifications, with some decreased effectiveness at eliminating massed hordes of infantry.

They also have strong superstitions around Drop Pod deployment, and prefer to avoid it except when necessary. Whence this superstition comes is unknown.

Organization

Other than the strong barriers to the advancement of younger brothers, the unusual distribution of psychic talent, and the changes to the order of training for initiates, the Black Thorns are a codex chapter. They do not hold to its strategic tenets with any reliability, but see no reason to deviate from its organizational tenets, since they seem broadly sensible and deviation would tend to cause conflict with other chapters and Imperial organizations.

Gene-seed

The distribution of psychic talent among the chapter is, as mentioned, unusually broad and shallow; it's rare to have more than one Librarian-class brother per company, and the Black Thorn Chief Librarian is often weaker than many chapter's ordinary Epistolaries. However, it's also rare for any company to have less than a full squad who have the power to wield a force weapon, and two or even three full squads per company with 'the mage-touch' is a common occurrence. Brothers with the mage-touch are usually shifted to assault specialties where their gift is more useful.

Like the Imperial Fists, the Sus-an Membrane is nonfunctional. Unlike them, the Betcher's Gland works normally while the Omophagea is almost totally nonfunctional. How the repair was accomplished, and whether the failure of the omophagea is related, is unknown, but other Sons of Dorn recognize the Thorns as being of their lineage and welcome them to the Feast of Blades, so while others may speculate on their geneseed's origins, their professed gene-family do not hold with it.

Battle-Cry

"Fall, and rise again as better men!"

The most closely-held secret of the chapter is that this is not spoken only to enemies in battle. It is also spoken to brothers in their times of crisis, most often shortly after a battle. Even there, it has a double meaning: Either to weaken, begin to succumb, and pull themselves back from the brink and 'tame the thrill', or to succumb and be executed, their geneseed used to create another brother.

Heraldry

The armor of the Black Thorns is navy blue, with details in white and silver. The design on the pauldron shows an old castle's gatehouse, in lighter blue on a white field, with the gate itself in navy blue. Ringing the gatehouse design is a crown of thorns, in pure black with details picked out with navy blue.