Overview
Rynn's World is the home of the Crimson Fists, nearly lost when an ork invasion and a single catastrophic magazine strike gutted the Chapter.
Its reconstruction is one of the Imperium's rare stories of recovery.
Proximity to the Charadon ork empire ensures the story is never allowed to end.
M41 and M42 status
Chapter world rebuilt from near-annihilation.
Fortified chapter world guarding the southern marches.
Timeline
WAAAGH! Snagrod, out of the Ork empire of Charadon, invades the Rynn system.
A rogue defence missile destroys the fortress-monastery Arx Tyrannus in the initial invasion; the Crimson Fists are all but annihilated yet endure.
Reconstruction of Crimson Fists strength is formally recognised.
Charadon instability keeps Rynn's World on permanent war footing.
Cartographic positions and several administrative details are intentionally approximate where published Warhammer sources conflict or provide no canonical coordinate system.