The Siege of Terra is the climactic battle of the Horus Heresy, where Warmaster Horus Lupercal and his traitor legions assaulted the Imperial Palace to overthrow the Emperor of Mankind. It’s the single most important event in Warhammer 40k history, deciding the fate of humanity and setting up the Imperium you see in the 41st millennium.
What was the Siege of Terra?
It was a massive assault on Holy Terra by the Forces of Chaos, led by Horus Lupercal. The loyalists, commanded by Rogal Dorn and other primarchs, defended the Imperial Palace for roughly 200 days (about 9.7 months) in M31.
The siege ended in a pyrrhic Loyalist victory. Horus was killed, but the Emperor was mortally wounded and interred in the Golden Throne. The Imperium survived, but it was forever changed.
Who fought in the siege?
On the Loyalist side: the Imperial Fists, Blood Angels, White Scars, a Dark Angels contingent, plus Imperial Army, Mechanicum, Custodes, and Sisters of Silence. Key commanders included the Emperor, Malcador, Dorn, Sanguinius, Jaghatai Khan, and Vulkan (hidden).
The Traitors fielded the Sons of Horus, Iron Warriors, World Eaters, Thousand Sons, Emperor’s Children, Death Guard, and elements of the Word Bearers and Night Lords, along with Dark Mechanicum and traitor Imperial Army. Horus led, with Perturabo, Angron, Magnus, Fulgrim, Mortarion, and others.
- Loyalists: Imperial Fists, Blood Angels, White Scars, Dark Angels, Custodes, Sisters of Silence
- Traitors: Sons of Horus, Iron Warriors, World Eaters, Thousand Sons, Emperor’s Children, Death Guard, Word Bearers, Night Lords
- Notable loyalist deaths: Sanguinius, Malcador, and many others
- Notable traitor deaths: Horus Lupercal, Horus Aximand, and others
Why does the siege matter?
It’s the foundation of the entire Warhammer 40k setting. The Emperor’s entombment on the Golden Throne, the rise of the Ecclesiarchy, and the Imperium’s paranoid, stagnant state all trace back to this battle.
The siege also ended the Horus Heresy and led into the Scouring, when the loyalists pushed back the traitors. The novel series of the same name covers it in detail.
The Siege of Terra novel series
Black Library’s Siege of Terra series continues the Horus Heresy novels, starting after The Buried Dagger. It’s the finale of that story, set during the battle itself.
The main series has 8 novels (the last split into three volumes), plus novellas and an anthology. It’s followed by the Scouring series.
| Book | Author | Year |
|---|---|---|
| The Solar War | John French | 2019 |
| The Lost and the Damned | Guy Haley | 2019 |
| The First Wall | Gav Thorpe | 2020 |
| Saturnine | Dan Abnett | 2020 |
| Mortis | John French | 2021 |
| Warhawk | Chris Wraight | 2021 |
| Echoes of Eternity | Aaron Dembski-Bowden | 2022 |
| The End and the Death: Volume I | Dan Abnett | 2023 |
| The End and the Death: Volume II | Dan Abnett | 2023 |
| The End and the Death: Volume III | Dan Abnett | 2024 |
Key facts
- The Siege of Terra was the final battle of the Horus Heresy, fought on Terra in M31.
- It lasted about 200 days and ended in a pyrrhic Loyalist victory.
- Horus Lupercal was killed; the Emperor was mortally wounded and entombed on the Golden Throne.
- The battle involved all nine traitor legions and several loyalist legions.
- The Siege of Terra novel series by Black Library covers the event in detail.
FAQ
How long did the Siege of Terra last?
About 200 days, or roughly 9.7 months, according to Lexicanum. It’s dated 119014-593014.M31.
Who won the Siege of Terra?
The Loyalists won a pyrrhic victory. Horus was killed, but the Emperor was mortally wounded and placed on the Golden Throne.
What is the Siege of Terra novel series?
It’s a Black Library series that concludes the Horus Heresy story, covering the battle in 8 main novels plus novellas and an anthology.