It is a vital industrial centre for the region, producing supplies used by many regiments of the Astra Militarum and Planetary Defence Forces across the Segmentum. Ichar IV's major exports include ore and fungal mycoproteins used as the nutritional basis of many Imperial foodstuffs.
At the beginning of the Second Tyrannic War, Ichar IV was infested with Genestealers. A Genestealer Cult, operating under the name of "The Brotherhood," instigated a rebellion on the planet that caught the attention of Inquisitor Agmar.
The Brotherhood had control of the planet by the time Agmar arrived in the star system. The Inquisitor petitioned the Ultramarines Chapter to help put down the rebellion. Marneus Calgar, the Chapter Master of the Ultramarines, arrived 39 solar days later aboard the Battle Barge Octavius.
Eventually, with the combined support of the Ultramarines, Ichar IV's Planetary Defence Forces and the Astra Militarum, the Inquisition successfully destroyed the invasion and cleansed the planet of all Genestealers.
One of the Astra Militarum units involved in the fighting on Ichar IV was the 13th Penal Legion, the so-called "Last Chancers." The 13th Penal Legion fought the Tyranids on Ichar IV and the bitter fighting resulted in terrible casualties for the Legion.
- Codex: Tyranids (2nd Edition), pp. 11–15
- Codex: Tyranids (3rd Edition), pg. 48, inside back cover
- 13th Legion (Novel) by Gav Thorpe
- Kill Team (Novel) by Gav Thorpe
- Annihilation Squad (Novel) by Gav Thorpe