Isstvan Sector

The Isstvan Sector is the administrative division containing the Isstvan System, an eight-planet system where the Horus Heresy ceased to be a rumour. The entry records the sector as a organisational container only. It does not serve as a second account of the massacres that took place within the system.

Two worlds of the Isstvan System define its place in the conflict. Isstvan III was destroyed by virus bombing, and Isstvan V was the drop site where Ferrus Manus died. Both worlds are recorded as children of the Isstvan System rather than of the sector. The Orrery map places the system under this sector, although some accounts of the setting locate it in Ultima.

The Isstvan Sector retains significance because later civil wars in the setting refer back to it as their point of origin. Unofficial maps preserve the Obscurus parent for the sector and keep Isstvan III and Isstvan V as children of isstvan-system.