[[Molech]] was one of the planets that the [[Warmaster]] [[Horus]] assaulted during his drive towards [[Terra]]. Horus became alerted to the planets significance when he regained a memory erased by the [[Emperor]], that of Molech having a gateway to the [[Warp]] that his Father had used to obtain power. Desiring such power for himself, Horus set a course to Molech.{{Fn|2c}} The [[Knight World]] was a major seat of [[Imperial]] power as the Emperor had left behind substantial forces to protect its unknown Warp Gate. A detachment of [[Blood Angels]] and [[Ultramarines]], Three [[Titan Legion]]s over a hundred [[Imperial Army]] regiments, an [[Imperial Armada]] [[Battlefleet]] of sixty ships, and [[Knight House]]s stood ready to face the Warmaster's onslaught, which included the [[Sons of Horus]] and [[Death Guard]] [[Legion]]s.{{Fn|1}}

Ultimately Horus' attempt to gain the powers of the Emperor was apparently successful, he stepped through the gate and emerged saying he had gotten exactly what he wanted. Molech was left to the Death Guard and [[Emperor's Children]] in the aftermath of his victory.{{Fn|2a}} After the battle aboard of his flagship the [[Vengeful Spirit]], a battle between the Sons of Horus and several escaped captives of the [[Knights-Errant]] broke out. Horus confronted [[Garviel Loken]] once more, but after Horus killed [[Iacton Qruze]] the Knights-Errant managed to escaped aboard the stealthship, the ''Tarnhelm''.{{Fn|2b}}

*[[Imperial Army]] — 100 Army Regiments, [[PDF]] Divisions, and Militia totaling 58 million troops. Commanded by [[Lord General]] [[Tyana Kourion]]

**The '''Northern Oceanic Theatre''' was commanded by [[Marshal (Imperial Guard)|Marshal]] [[Eodraki Hakon]]

**[[House Tazkhar]]

*[[Sons of Horus]] — Bulk of Legion

*[[Death Guard]] — Bulk of Legion

*[[House Devine]] (Defects later in the battle)

*[[Battles of the Horus Heresy (List)]]

*{{Endn|1}}: [[White Dwarf 190 (UK)]], pgs. 27-30

*2: [[Vengeful Spirit (Novel)]]: