Event · M31

Burning of Yssimae

The Burning of Yssimae refers to the destruction of a primitive frontier world by Lorgar Aurelian and his remaining Word Bearers in the closing months of the Horus Heresy. Following the failure of Lorgar’s attempted coup against Horus at Ullanor, the Primarch of the Word Bearers broke away from the main Heretic Astartes fleets, taking with him a remnant of his Legion and withdrawing into obscurity rather than joining the advance on Terra. Elsewhere, Zardu Layak led a separate host of Word Bearers onward toward the Throneworld to take part in the siege. Lorgar’s wandering fleet eventually made planetfall on Yssimae, whose tribal inhabitants received the Legionaries as divine visitors rather than conquerors. Over the following weeks, Word Bearers and native population together raised altars and circles of standing stone, through which Lorgar’s acolytes conducted divination rites intended to observe, from afar, the climactic battle unfolding around the Imperial Palace. Contact with Erebus, broken since Ullanor, was re-established through these workings, bringing confirmation of Sanguinius’s death at the hands of Horus and grim portents suggesting that the Emperor himself would not survive the fighting. Shaken by what the rites revealed, Lorgar gave the order to break camp and withdraw his fleet from the system. Before departing, he directed that Yssimae itself be destroyed, and the world’s surface was put to the torch, consuming the shrines, the altars, and the population that had sheltered the Word Bearers. Lorgar did not take part in the fighting on Terra itself; his presence throughout these events was confined to Yssimae and the ritual chambers raised there.

See where Burning of Yssimae occurred on the galactic map during the Horus Heresy.

Open in universe