The Ahriman Trilogy is John French’s Black Library series about Ahzek Ahriman, the exiled Chief Librarian of the Thousand Sons, picking up right after the Horus Heresy. It’s one of the best character studies in Warhammer 40k, and it’s grown well past its original three books.
What the ahriman trilogy actually is
the trilogy is three novels: Ahriman: Exile (2013), Ahriman: Sorcerer (2014), and Ahriman: Unchanged (2015). Together they follow Ahriman in the aftermath of the Heresy, after Magnus the Red exiled him for casting the Rubric, the spell that turned most of the Legion into dust-filled suits of armour.
French doesn’t just retell that backstory. He puts you inside Ahriman’s head as he hunts for a way to undo the Rubric, deals with rival warbands, and drags himself deeper into damnation. The prose is dense and atmospheric, and the series rewards readers who like their Chaos Space Marines complicated rather than cartoonish.
The books and stories beyond the trilogy
The series kept going long after Unchanged. Ahriman: Eternal arrived in 2022, and Ahriman: Undying followed in 2024, so calling it a trilogy is a bit of a legacy label at this point.
French also wrote a pile of short stories that slot in around the novels. Some follow Ahriman directly, while a run of them (The Dead Oracle, Fortune’s Fool, Hounds of Wrath, The First Prince, Gates of Ruin, and A Coin for the Carrion Thieves) follow the sorcerer Ctesias, who serves Ahriman.
- Novels: Exile, Sorcerer, Unchanged, Eternal, Undying
- Short stories: All is Dust, Hand of Dust, King of Ashes, The Dead Oracle, Fortune’s Fool, Hounds of Wrath, The First Prince, Gates of Ruin, A Coin for the Carrion Thieves
- Audiobook: Key of Infinity
- Collections: Ahriman: Exodus (short stories) and Ahriman: The Omnibus (first three novels plus shorts)
Where to start reading
If you want the smoothest ride, John French has a recommended order that weaves the shorts between the novels rather than saving them for last. Start with All is Dust, then Exile, then The Dead Oracle, Fortune’s Fool, Hounds of Wrath, The First Prince, and Gates of Ruin before Sorcerer. After Sorcerer comes Hand of Dust and King of Ashes, then Unchanged.
The later stories, Key of Infinity and A Coin for the Carrion Thieves, take place after Unchanged, so read them last. Eternal and Undying come after those.
Why it matters for Thousand Sons fans
Ahriman is the Legion’s most famous sorcerer after Magnus, and this series is the main place his post-Heresy story gets told. It fleshes out the Thousand Sons’ tragedy from the inside, showing what the Rubric cost them and what Ahriman is still willing to sacrifice to fix it.
It also sits alongside other Black Library books about Chaos protagonists from that era, like Graham McNeill’s A Thousand Sons and Aaron Dembski-Bowden’s Abaddon: Talon of Horus. If you liked those, this is the natural next step.
Key facts
- Written by John French for Black Library
- Core trilogy: Ahriman: Exile (2013), Sorcerer (2014), Unchanged (2015)
- Follows Ahzek Ahriman after his exile from the Thousand Sons
- Continued with Ahriman: Eternal (2022) and Ahriman: Undying (2024)
- Ahriman: The Omnibus collects the first three novels plus eight short stories
- Centres on Ahriman’s quest to undo the Rubric of Ahriman
FAQ
Do I need to read the Horus Heresy first?
Not strictly, but A Thousand Sons by Graham McNeill gives you the context for the Rubric and Ahriman’s exile. The trilogy explains enough on its own if you’d rather jump straight in.
Is the Ahriman Trilogy finished?
The original three novels wrapped up in 2015, but John French has continued the series with Ahriman: Eternal (2022) and Ahriman: Undying (2024), plus more short stories.
What’s the best way to read it?
Follow John French’s recommended order, which mixes the short stories in between the novels. If you want a simpler option, Ahriman: The Omnibus collects the first three novels and eight shorts in one volume.