Ollanius Pius is the Imperial Guard’s greatest saint, a Guardsman said to have thrown himself in front of Horus to save the Emperor during the Siege of the Imperial Palace. Whether he was a mortal soldier, a Perpetual, or a story the Imperium tells itself is exactly the point.
Who Ollanius Pius is
Pius is less a single historical person and more a myth the Imperium keeps retelling. The core story is simple: during the Siege of Terra, a lone Guardsman stood between Horus and the Emperor, and died for it. That act is said to have bought the Emperor the moment he needed.
Because the tale varies by source, the Lexicanum treats him as a mythological figure of the Imperial Creed rather than a fixed biography. Different accounts give him different names, origins, and even different species.
Why he matters
Pius is the Guard’s answer to the Space Marine heroes. He’s proof that an ordinary human, not a gene-forged demigod, can matter at the biggest moment in human history. That’s why his face shows up on regimental banners across the Astra Militarum.
The Order of Ollanius Pius is the highest military honour a Guardsman can earn. It’s a medal bearing an angelic youth with laurel leaves, awarded for acts at the very top of what a mortal soldier can do.
The versions of the story
The oldest and simplest version is Saint Ollanius Pius, the mortal Guardsman who died on Horus’s ship. This is the version the Ecclesiarchy and the Guard prefer, and the one painted on standards.
A later, more cosmic version makes him Ollanius Persson, one of the Perpetuals. In this telling he’s tens of thousands of years old, born in Nineveh, and has lived through everything from the Argonauts to the Gulf War. By the 31st millennium he’s a Calth farmer known as ‘Pious’ Oll Persson because of his Catheric faith.
A third version, Ollanius Piers, appears in some accounts and muddies things further. The sources don’t agree, and that disagreement is baked into the character.
- Saint Pius: mortal Guardsman, dies saving the Emperor.
- Ollanius Persson: Perpetual, possibly older than the Emperor, fought at Terra.
- Ollanius Piers: an alternate name used in some tellings.
Persson’s long life
If the Persson version is true, he’s one of the oldest beings in the setting. He claims to be roughly 45,000 years old by the Horus Heresy, which would put his birth around 15,000 BC, older than the Emperor himself according to older sources.
He served as the Emperor’s original Warmaster on prehistoric Earth, and later retired from the Imperial Army with land grants on Calth. He picked Calth partly because the New Empire under Roboute Guilliman was more tolerant of his religious beliefs.
Key facts
- Ollanius Pius is the legendary Guardsman said to have died defending the Emperor from Horus at the Siege of Terra.
- He’s venerated as a saint by the Imperial Guard, and his image appears on regimental banners.
- The Order of Ollanius Pius is the Guard’s highest military decoration.
- Sources disagree on his identity: mortal saint, the Perpetual Ollanius Persson, or Ollanius Piers.
- The Persson version claims he’s around 45,000 years old by the Horus Heresy and once served as the Emperor’s first Warmaster.
FAQ
Was Ollanius Pius a real person in 40k?
In-universe, nobody can prove it. The Imperium treats him as a saint, but the sources contradict each other on whether he was a mortal Guardsman, a Perpetual, or a legend built up over ten thousand years.
Is Ollanius Pius a Perpetual?
One major version of the story says yes, identifying him as Ollanius Persson, a Perpetual who may predate the Emperor. The simpler Guard legend keeps him as an ordinary human.
What’s the Order of Ollanius Pius?
It’s the highest military honour in the Astra Militarum, named after him and awarded for extraordinary acts of sacrifice in the Emperor’s service.