Mortarion, the Emperor’s fourteenth son and Primarch of the Death Guard Legiones Astartes was doomed the moment he crash landed on Barbarus. A brutal world ruled over by petty warlords who subjected its people to horrors unimaginable for sport and the furthering of their own deluded schemes for power.

His crash landing drew the attention of one such warlord who, recognising the child’s strength, locked him away in the mountains to live a life of deprivation and abuse at the hands of a power-hungry maniac with dreams of domination. Even when the warlord took the time to teach Mortarion anything it was a brutal and relentless style of warfare that he sadly became famous for. At the hands of such a brute any hope of Mortarion finding the nobility of war and honour in sacrifice was lost. All he saw was the necessity of sacrifice and the continuity of war.

And the truth of his existence up to his escape and descent down the mountains was that he was little more than a weapon. An unstoppable force rolled out to win the war then incarcerated once more. His existence was not entirely dissimilar to that of Angrons. However, whereas Angron had Chaotic artefacts implanted in his brain overtly dooming him to the Red Path, Mortarion was exposed to necromantic powers and armies made up of what was most likely lesser daemons. Combined with the toxic atmosphere I suspect Mortarion not only was compromised of mind but also of body beyond the obvious gaunt appearance.

His escape brought him into contact with the pawns and playthings of the warlords – humans. However it was not an easy integration. Seeking kinship and acceptance Mortarion was, instead, met with suspicion and never really accepted into the community despite all his efforts. Even though shunned, he continued to work for the humans, finally winning their acceptance after he successfully defended the town from a warlord and his minions. However, as he moved from township to township lending aid and uniting them to the cause of liberation he was still a man apart.

Whereas other Primarchs, such as Guilliman and Dorn used this to their advantage, being an example to all and an immovable bastion of strength, Mortarion pushed himself all the harder, throwing himself into the thickest fighting in an attempt to be accepted as one of them. However Mortarion was feared and his methods of war, learned from tyrants, did not earn him the love or admiration of those he commanded. For all his efforts he was still alone. Only his closest and most skilled warriors, the Death Guard, came close to understanding him as a person, but his brooding humour prevented them from forming any meaningful bond.

Mortarion was an abused soul. Even when the Emperor came to Barbarus he manipulated his son’s hubris and dogged determination to join his crusade. And once at the head of the Death Guard he was left to instil the same sense of resigned and dogged approach to war that he learned at the hands of his abusers. But more than that, Mortarion desired, more than anything, for all men to be free. His treatment had instilled in him a deep-seated resentment for authority and control, teaching his sons self-reliance and keeping them at arm’s length lest he become ruler rather than leader of his legion.

And as the crusade wore on and he was forced to subjugate planet after planet in his father’s name he started to brood on whether or not he had swapped one tyrant for another. To a degree, he had, as you cannot rule a galaxy without rules, or one free of the lure of Chaos with restrictions and penalties. But he failed to understand the necessity of the galaxy the Emperor was trying to create or Mortarion’s place in it. The psychological wounds he suffered on Barbarus over the years split wider and wider and eventually began to fester.

Thanks to the slow rot that had set in from Mortarion’s earliest days coupled with his profound sense of isolation drove him into the fraternal arms of Konrad Curze, a soul just as tortured and troubled by the notion of empire building, and Horus. He found Horus’ charisma, ease with the men both Astartes and mortal alike, and his fervour and zeal on the battle field quite intoxicating. Horus nurtured this admiration as much for Horus’ own ego as it was about drawing allies around him.

At Ullanor Mortarion’s displeasure reached tipping point. The self-indulgent display of martial might was all the evidence that he needed that his father was no better than warlords he had fought back on Barbarus all those years ago, but on a much grander scale. He also realised that he was a product of that grand and ambitious scheme. It appalled him to be an instrument of tyranny once more but this time, willingly but unwittingly. And throughout he had thrown his legion against his fathers enemies, bludgeoning all into submission, heaping abuses on his sons in the form of war and death, as he had had heaped upon him. And all in the name of his father.

I honestly believe had Horus not calmed him at that point he would have broken away himself. When Horus declared war on his father Mortarion was the first to sign on, siding with the one person who had taken the trouble to nurture him and attempt to shed some light on the darkness Mortarion carried in his soul. Of course we know that Horus was using Mortarion and that only got worse as the Heresy took hold.

Mortarion’s approach to war meant that his Legion was destined to be clog the gears of the Imperial war machine and he was once more at the mercy of a tyrant, only this one was driven by blood lust and the whisperings of the warp. And it was these powers that would ultimately hold Mortarion in bondage. As we know he and his legion were forced to give themselves to Nurgle less they suffer an agonising death across the span of millennia. With a final act of desperation to save his sons – the one true paternal act Mortarion ever displayed – he found himself at the mercy of a cruel God.

All Mortarion ever wanted was to feel like he belonged. First it was with his adoptive father. Striving to impress the cruel warlord. Then it was the mortals who dwelled on the lowlands of Barbarus. Then his father and brothers and even his own sons. With all of them he felt distant. This was partly due to the abuses he suffered on Barbarus but because he failed to understand his nature. Mortarion was born to be free of structure and imposition. His aloof character was destined for far loftier goals when the crusade was done but his experiences tainted everything he saw and where he saw order and enlightenment he saw tyranny and closed mindedness. And wherever he went in his life he found himself at the mercy of those that seek to manipulate his idealism, for good or for ill, until he was forced to give himself to one of the greatest tyrants sentient life has ever known.