A feral world in the Drusus Marches of the Calixis Sector. This lush and verdant backwater world features diverse landscapes, from snowy peninsulas to arid deserts unspoiled by industry or exploitation. Monrass is populated by burgeoning archaic empires that predate the Angevin Crusade and have only in recent centuries mastered iron-smelting and chariot combat. The planet’s “governor” is an Administratum satrap, sitting in an high orbital tithing station, who interferes only to occasionally levy troops and foodstuffs for the Imperium’s due, while the only other off-worlders known to the people are a handful of missionaries determined to bring the Emperor’s light to the benighted natives.
Ignis Aeternus WH 40K campaign notes 