Rhoie is the fourth and most important planet in the Rhoie system. It is a green tempered planet, dotted with hive cities amid rolling savannahs and scattered forests. It consists of four major continents: Braaka and Regga in the southern hemisphere and Trikerala in the northern hemisphere. The glacial North Island holds the geographic north pole of the planet. Rhoie has a range of metal and mineral mines, as well as a large timber industry and is of vital importance to Imperium.
The capital on Braaka is the hive city Braakapolis, which is also the only hive on the continent. Regga is dominated by the hive Reteket, which has the largest space port on the planet. Trikerala is the largest and most influential continent. The capital Hive Andeonium is surrounded by the Dragonback mountain range, with its vast resources of valuable minerals and metal ore.
A large uprising recently plunged the planet into anarchy, and the Space Wolves and Blood Angels Chapters sought to aid the Imperial Guard in defeating a Chaos invasion. This failed and the Chaos troops conquered Hive Andeonium. By ritually slaughtering most of the inhabitants, they opened a gateway to the Warp in the old Imperial cathedral. Daemons poured onto the planet, as the Imperial troops were forced to besiege the hive and await reinforcements.
Smaller victories to the Imperial side lead to the front lines being moved a little bit, but the siege was not broken. Fresh Imperial Guard regiments were brought in, as well as Inquisitors and additional Space Marines. Skirmishers between various factions, including Tyranids, Eldar, and even Tau, in the countryside surrounding the hives were reported. A bold attack over Kerala’s Grave opened a bridgehead for Imperial troops to deploy into the city once more.
After years of grueling siege fighting and the increasing Warp Rift spewing out an endless number of Daemons, Inquisitor Lord Ahrgon Hall approved an Exterminatus order. The Imperial forces were hastily evacuated, together with a large proportion of the civilians on the planet, before Battlegroup Virago bombarded the planet and Hive Andeonium from orbit with cyclonic torpedoes.