Ferrozoica is chiefly known for two outbreaks of violent relations with its rival hive of Vervunhive. The first of these was a 'Trade War' in which Zoica was defeated. Some time afterwards the entire hive was tainted by the Ruinous Powers and 90 years after the Trade War nearly 100% of the population was rounded up to fight for Chaos.
They attacked both Vervunhive and Vanick Hive, the latter being destroyed when Ferrozoica targeted it with Nuclear weapons. Vervunhive suffered a mass infantry and war-machine assault, and the Zoican forces were on the verge of winning when their mobile command centre, dubbed "The Spike" by Imperial commanders, was infiltrated by Colonel-Commissar Ibram Gaunt and his strike force of Tanith, Volpone and Scratch Company troops and destroyed.
When the command centre was destroyed the Chaos forces fled back towards their home hive but were obliterated by a combined force of Imperial Guard, Space Marines, Titan Legions and Imperial Navy. Ferrozoica itself was engaged from orbit by the Imperial Navy and flattened.
The livery of Ferrozoica is ochre, and its corrupted soldiers are described to be equipped with lasguns and guard equipment, wearing ochre fatigues and snarling skull-like helmets. They used a variety of imperial tanks and exotic war-machines, the latter created by their leader, Heritor Asphodel. Their vehicle crews were dressed in black fatigues and did not wear helmets, revealing their heads to be nearly covered in implants which relayed Chaos chatter to them from The Spike, keeping them under Chaos control.
After the Siege of Vervuhive ended, several refugees from the surrounding countryside drifted into Vervun. Some of these unregistered citizens were discovered by the Arbites to be from Ferrozoica, raising the dangerous possibility that they were carrying Chaotic taint into the still-damaged city.