The Battle of Prospero, also called the Burning of Prospero, was the Imperial assault on the Thousand Sons’ homeworld in 004-005.M31. It pitted Leman Russ and his Space Wolves, alongside the Custodes and Sisters of Silence, against Magnus the Red and his legion. The attack left Prospero in ruins and pushed the Thousand Sons toward Chaos.
Why the Emperor turned on Magnus
The roots of the battle go back to the Council of Nikea, where the Emperor banned psychic powers among the Legiones Astartes. Magnus the Red and his Thousand Sons were the legion most affected, since sorcery was central to their identity. Magnus felt the ruling was a personal judgment against him.
Magnus withdrew his legion to Prospero. Then he learned through a vision that Horus would betray the Emperor. Desperate to warn Terra, he used forbidden sorcery to send a message, but the effort shattered the Emperor’s psychic wards and wrecked a vital project. The Emperor decided Magnus had to answer for it.
The Space Wolves are sent to Prospero
The Emperor dispatched Leman Russ and the Space Wolves to bring Magnus to Terra. Russ was joined by Constantin Valdor and the Adeptus Custodes, plus the Sisters of Silence, whose blank nature nullified psychic powers. The force was overwhelming.
Horus, already turning traitor, may have altered the orders to push Russ into destroying the Thousand Sons outright rather than arresting Magnus. Sources differ on exactly how the orders were changed, but the result was the same: the Wolves came to Prospero ready for war.
The burning of Tizca
The Space Wolves and their allies struck the Prosperine capital, Tizca. The Thousand Sons, caught off guard and outnumbered, fought back with sorcery and courage. The Sisters of Silence proved devastating, cutting off the legion’s psychic edge.
Magnus initially refused to fight his brothers, but as the city burned he finally took the field. He dueled Russ and was defeated, though not killed. The battle ended with Tizca in ruins and the Thousand Sons shattered.
- Prospero’s capital, Tizca, was reduced to ash and rubble.
- Roughly 90% of the Thousand Sons were killed or scattered.
- About 30 million civilians and Prosperine Spireguard died.
- Survivors, led by Ahzek Ahriman, teleported to the Planet of the Sorcerers.
What happened after
The survivors of Prospero fled into the warp and eventually settled on the Planet of the Sorcerers, where they fully embraced Chaos. The Thousand Sons became a Traitor Legion, bound to Tzeentch.
The battle also deepened the rift between loyalists and traitors. Russ and his Wolves believed they had done their duty, but the brutality of Prospero haunted them. For the Thousand Sons, it became a wound that never healed.
Key facts
- The Battle of Prospero took place in 004-005.M31 during the Great Crusade.
- The Space Wolves, Custodes, and Sisters of Silence attacked the Thousand Sons.
- Magnus the Red was defeated by Leman Russ but survived.
- Around 90% of the Thousand Sons were killed or scattered.
- Survivors fled to the Planet of the Sorcerers and later served Tzeentch.
- The battle was a turning point that pushed the Thousand Sons into the Horus Heresy.
FAQ
Who fought in the Battle of Prospero?
The Space Wolves, Adeptus Custodes, and Sisters of Silence attacked the Thousand Sons on their homeworld of Prospero.
Why did the Space Wolves attack Prospero?
The Emperor ordered Leman Russ to bring Magnus to Terra after Magnus broke the ban on sorcery. Horus may have twisted the orders to demand destruction instead of arrest.
What happened to the Thousand Sons after the battle?
Most were killed. The survivors fled to the Planet of the Sorcerers and became a Traitor Legion dedicated to Tzeentch.