The Periphery is the most remote of the several sub-sectors of the Calixis Sector, being the only sub-sector to not directly share a border with the Golgenna Reach, of which it is located spinward. It is bordered by the Malfian Sub-sector and the Markayn Marches. As it is a remote region, it is home to many isolated planets and frontier worlds that struggle to survive in the face of their marginalization.
The Arch-Diocese of both the Periphery and the nearby Halo Stars is overseen by Cardinal Fortis, who rules not from a planet as his seat of power, but a ship, the Pax Calixis. All Ecclesiarchal matters of these two regions falls under his jurisdiction, and just as the regions themselves are far-removed from the goings-on of the Calixis Sector, so to is he removed from the politics of the Sector Synod.
- Avitohol is a Xenos World in the Calixis Sector. Originally the sight of battles between Orks and the Imperium, the world has since fallen under the heel of the Warboss Ghenghiz Grimtoof, who has enslaved the Human population
- Cyclopea is a civilised Forge World in the Calixis Sector.
- Ganf Magna is a Frontier World in the Calixis Sector. It is contested by Feral Orks and Polygum is exported from here.
- Kalf is a Frontier World in the Calixis Sector. It is the home of the Sand Devil.
- K’otal is a mining world in the Periphery of the Calixis Sector
- Kulth is a War World in the Calixis Sector. It has been fought over for 83 years since the first Ork invasion.
- Misery IX was recently visited by the Tyrant Star and in its wake only madness and ruin remain.
- Sinophia is a Frontier World in the Calixis Sector. Initially a launching site for Rogue Trader excursions prior to the Angevin Crusade, Sinophia has recently fallen into an economic depression which is slowly leading to its complete depopulation.
- Sisk is a Feudal World in the Calixis Sector.
- Sleef is a Dead World in the Calixis Sector. It is uninhabited and strange warp vibrations occur here.