Grimoire Heralds

The Grimoire Heralds are a "break-off" independent Sect of the Thousand Sons originating from an unknown Cult. The Grimoire Heralds roam the galaxy, obsessed with bringing about their unknowable "Grand Plan" by creating upheaval, gathering knowledge, and collecting artifacts.

History
The history of the Grimoire Heralds is complex and often self contradicting. What is known is that some time after the Horus Heresy a Thousand Sons Sorcerer under the name of Samael claimed to have had a revelation supposedly inspired by Tzeentch himself. He gathered the forces of his Sect and 'split-off' from the Thousand Sons in order to intact his envisioned "Grand Plan".

Organisation
The Grimoire Heralds are divided into eight Warcovens that contain roughly a hundred Rubicae each and are lead by a Magister. The Magister of the First Warcoven serves as the Archmagister Warband as a whole.

The forces of the Grimoire Heralds are bolstered by a host of more than ten thousand cultists and countless Daemons.