Laomedeia

Laomedeia is a moon of Neptune in the Sol System. By the time of the Horus Heresy Neptune’s moons held human colonies, and during the Solar War Chaos cultists released toxic gas into Laomedeia’s habitats.

After the Siege of Terra the moon sheltered Traitors fleeing the system, among them Word Bearers who, concealed by sorcery, began a project they called the Great Work, a colossal device intended to rekindle the power of the warp within the Sol System. Perturabo, summoned by the Iron Warrior Ortag Theokon, came to the moon from his flagship Iron Blood, crushed the Word Bearers and stripped Laomedeia of its resources and personnel before withdrawing. Neptune’s habitations and moons were left devastated by the Solar War and by the Ultramarines bombardments that followed the relief of Terra.