Burning of Prospero
| The Battle of Prospero | |
| Date | 004.M31 |
| Scale | Planetary |
| Theatre | Horus Heresy |
| Status | Pyrrhic Space Wolf victory |
| Belligerents | |
| Imperial Censure Host | Thousand Sons |
| Commanders and Leaders | |
| The Primarch Leman Russ, Constantine Valdor, Jenetia Krole | The Primarch Magnus the Red, Ahriman |
| Strength | |
| ~73,200 Space Wolves, 5000 Sons of Horus, 982 Custodians, 3000 Sisters of Silence, over 54,000 human infantry from various regiments, 12 Battle Titans, 5 Psi-Titans, over 2000 Mechanicum Secutarii and Tech Adept staff. | ~62,200 Thousand Sons, the Prosperine Guard (~85,000 soldiers), Zhao-Arkhad Taghmata (~8000 warriors & automata), 12 Battle Titans, millions of citizen reservists |
| Losses | |
| 49,000 total. 23,000 Space Wolves KIA and 23,000 Imperial Army KIA. Severe Custodes and Sisters of Silence casualties | Very heavy. 90% of the Thousand Sons KIA. 30 million Prosperine Spireguard and civilians wiped out |
| Outcome | |
| Razing of Prospero, withdrawal of the Thousand Sons to Sortiarius and the sundering of Magnus the Red. | |
