Maeleum

Maeleum was a daemon world held by the Sons of Horus after the Horus Heresy and the site of the Monument raised around the corpse of Horus. It is described as a rust graveyard, and the Sons of Horus made it their principal holding in the period following the Heresy.

The Sons of Horus built the Monument on Maeleum to enclose the remains of their primarch. The Emperor’s Children, led by Fabius Bile, later attacked the world, destroyed the fortress and took the corpse. Abaddon subsequently abandoned the ruined fortress when he reorganised the warband as the Black Legion.

Maeleum’s standing rests chiefly on its association with the remains of Horus, which the Monument housed until their removal. Its later history is one of abandonment and depletion: Thagus Daravek cored the planet to obtain material for mass-driver shot.