Sabatine was the Chapter homeworld of the White Consuls Space Marine Chapter, perhaps the most far-removed from Ultramar of all of the XIII Legion's Primogenitor Successor Chapters. This world lies in the Segmentum Pacificus, far to the galactic southwest of the Eye of Terror. As such, it is a rare thing indeed for the Chapter's brethren to appear in the court of Marneus Calgar, and when it does it is a great cause for celebration. Very little is known about Sabatine, due largely to the secretive and defensive nature of the White Consuls.
The White Consuls, alongside about twenty other Chapters known as the Astartes Praeses, are sworn to protect the Imperium from the depredations of the servants of Chaos -- in particular the Traitor Legions -- who periodically spew forth from the Eye of Terror on one of their devastating Black Crusades. So that they may prosecute their duty as sentinels of the Eye of Terror whilst maintaining operations against a wide range of enemies of the Imperium, the White Consuls have instigated a highly unusual policy. The Chapter is ruled not by a single Chapter Master, but by two. One of these oversaw the defences of Sabatine and commands a standing force ready at a moment's notice to respond to Chaos incursions through the Cadian Gate, while the other is responsible for the operations of the Chapter's forces in war zones further afield. This equal division of command works well for the White Consuls, although it is doubtful whether it is sanctioned by any entry in the Codex Astartes. Perhaps the Chapter's great separation from its Progenitor Legion means that it has not been challenged on the matter. In addition to its homeworld of Sabatine, the White Consuls also maintain sovereignty over several nearby star systems which they hold as protectorates, such as the Boros System and its central world of Boros Prime, site of a massive incursion by the Word Bearers Traitor Legion in the late 41st Millennium.
Unfortunately, after the fall of Cadia and the birth of the Great Rift that cut the Imperium in half at the climax of the 13th Black Crusade in 999.M41, the White Consuls, like so many Space Marine Chapters, found themselves cut off from Imperial reinforcements. Eventually Sabatine was overrun by the surging tide of the Archenemy and it was destroyed by the Forces of Chaos. Luckily, the bulk of the White Consuls managed to flee before Sabatine was lost, unlike many of their fellow Astartes Chapters in similar circumstances. The effect this had upon their unusual Chapter hierarchy remains unknown.
- Codex: Space Marines (5th Edition)
- Deathwatch: Rites of Battle (RPG), pg. 56
- Warhammer 40,000: Rulebook (8th Edition), pg. 51