From Lexicanum

Map	Basic Data		Planetary Image
	Name:	Mordian
	Segmentum:	Segmentum Obscurus
	Sector:	Unknown
	Subsector:	Unknown
	System:	Mordian
	Population:	Unknown
	Affiliation:	Imperium
	Class:	Hive World
	Tithe Grade:	Unknown

Information

Mordian is a hive world renowned as the homeworld of the Iron Guard. The Mordian day is the same length as the Mordian year, the small planet turning upon its axis once each time it completes a circle of its sun. Consequently, half of the planet is in perpetual darkness; the other constantly burned by the harsh sun. All life is on its dark side.

Mordian's hundreds of millions of inhabitants live on a land surface barely one tenth the size of Earth. Its hive cities are characterized by pyramidal, multi-leveled towers rising like mountains towards space. The government is known as the Tetrarchy, and strictly controls and rations the planet's meager resources. Mordian naturally breeds discontent, and the Mordian Iron Guard must constantly stand against anarchy and rebellion.

The greatest threat faced by Mordian came as a result of a conspiracy among Chaos cultists. Summoned by a spell, ships from the Eye of Terror poured Chaos Marines from the skies and daemons appeared within the streets. The Iron Guard put up a gallant resistance against the attack but were pushed back deeper into the heart of the capital, until in a final stand they took position around the Tetrarchal Palace itself, the last strongpoint on the whole world.

While the Iron Guard had fought, beyond the orbit of Mordian psykers had also fought to counter Chaos's hold on the planet. Its hold was already tenuous, and the Iron Guards' resistance had given the psykers time to finally break the hold. Chaos was defeated; Daemons and Chaos Marines dissolved before the defenders' eyes.

Sources

• WD184, Mordian Iron Guard, by Rick Priestley