Ollanius Pius is essentially a mythological figure of the Imperial Creed, and is likely a reference to a mysterious individual named Ollanius Persson, who played a role during the Horus Heresy that has yet to be fully documented.
Saint Ollanius Pius
Ollanius Pius is a legendary figure, said to be a Guardsman who sacrificed his life to save the Emperor during the Siege of the Imperial Palace. He is considered a Saint within the Imperial Guard and his image is often displayed on regimental banners.
Ollanius Persson, also known as 'Pious' Oll Persson because of his devout belief in the Catheric religion, was a civilian resident of Calth, in the Ultramar system, at the outbreak of the Horus Heresy, who made his way as a farmer. Before this, he had been a private soldier in the Imperial Army who earned the right to retire; being gifted with service-shares for a plot of land proportionate to his years served (rounded down - the Army always rounded down), he decided to cash them in on Calth, taking on twenty hectares. He chose Calth for two main reasons; the first was that if service-shares were used to buy land on a world newly-opened for colonisation, travel-fares to that world were paid for. The second was that, out in the farther reaches of the Imperium, under the banner of the "New Empire" being forged by Roboute Guilliman and his Ultramarines, Persson felt that it would be easier to practice his faith without incident; religious faith was widely looked down upon in the Imperium as unscientific nonsense. Persson settled down on Calth, living comfortably enough for eighteen years. The only indicators of his past as a soldier were the fading tattoo on his arm, the battered lasrifle mounted on his wall, and the company of an ex-Army loader servitor named Graft, that could not be dissuaded from referring to Oll as 'Trooper Persson'. To others, including his neighbours and several employees, he was just old 'Pious Oll'.[3a]
Oll was present on Calth when the Word Bearers Space Marine Legion attacked the Ultramarines during the Great Betrayal. The initial strikes from impacting orbital debris (once ship yards and vessels of the Ultramarine fleet) reminded him, terrifyingly, of his last campaign in the Army, upon the world of Chrysophar. Oll turned to his faith to help him survive during this time, and was knocked unconscious shortly after uttering a prayer to his god. During this unconscious period, Oll appeared to dream of being visited by an old friend of his; John Grammaticus. Unwilling to converse with Grammaticus, Oll attempted to carry on preparing breakfast for his wife; Grammaticus was forced to remind him that his wife died long before he joined the Army. Long before the last time he joined the Army, to be exact. Oll also refused to listen to John's attempts to remind him of their old brotherhood-in-arms in such conflicts as those that took place at Anatol Hive and the Panpacific on Terra, "several lifetimes ago". Finally, Grammaticus used Oll's status as one of the few remaining Perpetuals in existence and the onus that came with it to somewhat reluctantly guilt him into paying attention.
Grammaticus delivered the news that without their intervention, "he" was going to lose the war, and that if "he" lost, the human race would lose. Grammaticus urged his old friend to leave Calth via "Immaterium sidestep" and gain an object for him. When Persson asked where he was supposed to go, Grammaticus replied that he would show him:[3b]
Persson then found himself transported from his comfortable dream-environment to one of horror; aboard a space vessel at war, but a vessel that was unnatural and disturbing, orbiting a burning Terra. Entering a massive chamber, he encountered a dead angel lying upon the floor, his brutal killer standing nearby. Taken aback by the unholy appearance of the angel's murderer, he raised his Catheric symbol and audibly renounced the Evil One that stood before him. The killer took a step towards Oll, but stopped, his attention caught by something held in Persson's hand. At that moment, a golden light coming from behind Oll flooded the chamber, a light Oll recognised as one he used to know... but weaker, and sullied. Announcing that he had seen enough, he heard Grammaticus speak as if bringing him to wakefulness.[3b]
Waking up in what was left of his lands, Persson resolved to escape from the ongoing Battle of Calth, aiding a number of other survivors on the way, many of whom banded together with him and accompanied him off-world. Before leaving, he managed to acquire an athame ritual blade from a Chaos Cultist that he believed may be the item he was supposed to fetch, to be used for something utterly important. Persson left Calth by use of apparent sorcerous techniques; he used the athame to open what appeared to be a form of warp-gate and stepped through.[3c]
A detailed explanation of the term "Trivia" and "Varia" as used in the Lexicanum can be found here.
Ollanius Pius is a mythic figure to the common people of the Imperium, and in some ways to the Warhammer 40,000 community at large; he is often referred to as the man whose selfless actions aboard the Warmaster's battle barge ultimately led to Horus's defeat, without great evidence to back this up, by both the fictional group and the real one. The reasoning for this in-universe is that his story is presented as a legend of a long-ago Saint. Out of universe, it involves previous tellings of the Heresy story (published before the current novel series) that have variously presented a Legiones Astartes Terminator (and then, in a retcon) a member of the Emperor's Custodian Guard as stepping in between the humbled Emperor and the triumphant Horus, only to be horrifically slain. It is this death that then spurs the Emperor onto finally defeating Horus once and for all. It is commonly interpreted by the fandom that Pius' believed sacrifice actually took place aboard the Warmaster's Battle Barge, and that he was another iteration of the Terminator/Custodian character. This interpretation appears to be supported by the latest published material, which places a character called Ollanius Persson into this confrontation, albeit if only in a vision and in a somewhat different manner.
- Despite the wording of the source material about Ollanius Pius being a Guardsman (there was no such thing during the Heresy; Imperial human soldiers were members of the Army) who interjected himself between the battling leaders at the Imperial Palace (Horus and the Emperor only fought once, upon the Warmaster's Battle Barge, not at the Palace), this is not actually much of a problem for in-universe rationalisation - as the idea of Pius being a legend would allow for such inconsistencies with since-forgotten historical fact.
- Ollanius Persson is a very ancient being: he makes first-hand reference to historical and mythological events such as the Siege of Verdun (during the First World War), the Battle of Austerlitz (during the Napoleonic Wars) and being one of the Argonauts, amongst others.
- 1: Warhammer 40,000: Compendium, pg. 38
- 2: Rogue Star (Novel) by Andy Hoare, [Needs Citation]
- 3: Know No Fear (Novel) by Dan Abnett