Astartes Praeses

The Astartes Praeses are supposedly a group of twenty Space Marine Chapters whose sole purpose is to guard the Eye of Terror.

The Mythos Angelica Mortis makes a single reference to twenty original Chapters created from the unique gene-seed of those Chapter Masters who had not fallen to Chaos during the Horus Heresy, and whose role would be to stand guard around the Eye of Terror and support Cadia and the Inquisition at need (Codex: Eye of Terror). They were evidently created fresh rather than assembled from the remnants of the Space Marine Legions, like many of the other Second Founding Chapters, to reduce the possibility of corruption.

Though no comprehensive list has ever been assembled, the current known members of the Praeses are:

the Excoriators; the Marines Exemplar; the Night Watch; the Relictors; the Subjugators; and the White Consuls.