Ichar IV was a planet once colonized by the Imperium of Man during the years around 40,000 A.D. It was invaded by Genestealers, who then created a Genestealer Cult that became so strong that they eventually began to conduct sabotage missions and start riots. Although it is unknown whether they knew it or not, this was in order to sow discord or even to eventually subdue planetary defenses in order to prepare for the invasion of a Tyranid fleet. Eventually, the Tyranid did consume the planet.