Ultima Segmentum

Ultima Segmentum is one of the Imperium's five Segmentum Majoris, the eastern cube of Ultramar, the Eastern Fringe, the Tau Empire's neighbourhood, and the first Tyranid landfalls.

Macragge, Baal, Octarius, Badab, Thramas, Vidar, Korianis/Aurelia, and a third of the galactic map sit here. Hive Fleet Behemoth named itself on Tyran; Guilliman's realm is still the Imperium's eastern argument that order can hold.

Ultima Segmentum still matters as Terra's eastern wall and the Fringe's remaining hope. Unofficial fan summaries keep a null parent and skip the mashed duplicate id ultima-segmentum-occident-declining.