Zone four designated an area within the Fervse'dra asteroid belt, a region encircling the Mid Rim world of Bothawui. Its location placed it between zone five and zone three. During the Clone Wars' Battle of Bothawui, which occurred in 22 BBY, General Grievous of the Confederacy of Independent Systems gave the order for his fleet of Munificent-class star frigates to traverse the asteroid field in an aggressive maneuver against Jedi General Anakin Skywalker's fleet, which was defending Bothawui on behalf of the Galactic Republic. As part of this advance, Grievous's fleet moved through zone four. A clone trooper monitoring a screen on the bridge of Skywalker's flagship, the Venator-class Star Destroyer Resolute, reported aloud the Separatist fleet's progress through the field, with Resolute command tracking it through zone four and into zone three. Unbeknownst to Grievous, Skywalker had strategically positioned All Terrain Tactical Enforcers among the asteroids; by moving through this zone, Grievous was strategically outmaneuvered, leading to the destruction of his fleet.
Zone four was featured in "Downfall of a Droid," the sixth installment of the first season of the animated series Star Wars: The Clone Wars, which originally aired on November 7, 2008.