Zunus

(general TLDR goes here)

History
Zunus, in ages past, was formerly under the authority of High king (cool name) Algonquin, ruler of Zunus of the Alteria system and lord of the Knights of House Algonquin. The planet served as a Vassal World for the isolated Forge World of Hephaestia, and existed as both a source of resources and menials until it entered into into rebellion in 611.M32.

The ambitious move came amidst the WHAAG! of The Beast, and the Mechanicum rulers were unable to respond adequately. Initially one of the lesser houses rose up and Lord Kling declared himself High Kinging of the world and that the system was his Klingdom, claiming the resources and factories upon the world for himself. This would not last, as House Algonquin swiftly struck him down and then staked their own succession claim, ruling over the populace as their own personal fief. After the defeat of the WHAAG! and subsequent Fourth Founding, the Knights of Steel, descendants of the Dark Angels, fell upon the system. It was not an easy victory for the space marines. The world was possessed of powerful technology gained from the beneficence of Hephaestia, and thus posed stern resistance to the invading Knights and inflicted terrible damage to the chapter, killing almost half of the chapter.

As the war raged on, huge sums of resources were utilized by the defending rebels during the five year campaign to fuel the captured foundries in a desperate bid to hold off the Knights of Steel. Swathes of the world were reduced to ruin as the Knight House of Algonquin stormed across the world. As the remnants of The Beast’s forces were slain, Hephaestia managed to reach the now shattered world and found themselves in a conundrum with what to do with it. Surrendered forces held prisoner by loyalist military forces spoke of the Knights of Steel and their victory over them. After executing one third of the population for their heresy, diplomatic relations were extended unto the Knights of Steel and an alliance was made and terms of alliance drawn. The mathematics of such a compact were simple, the alliance with an Astartes Chapter was worth more to the Mechanicum then the remaining resources upon the world, and the system was turned over to the rulership of the chapter with the tech priests of Hephaestia taking up a permanent presence within the system on the capital world’s moon. And since then the foundries run constantly to manufacture all the goods required for the chapter and the world beneath them.

House Algonquin is now sworn to the very marine chapter which crushed them, oathbound eternally and they fight together.

(This needs some updating)

Has a dank moon
Caberiria

A former off planet retreat and military base of Zunus, the great forge fanes of the world are built around four great bastions long since converted to the worship of the Machine God. Prior to the occupation of the cult mechanicus, these fortresses contained huge reserves of men and machines, and their underground tunnel networks are as expansive as the defense laser arrays which stud the surface. Stuff happens here.