Little is known of the Promellians; they and the Menthars fought to their mutual extinction in a major war approximately 1,000 years ago. The war was notable for the extreme destructiveness achieved with the relatively primitive weaponry of the time.

In 2366 the Enterprise-D found a Promellian battlecruiser adrift in an asteroid field. The ship was still intact, and the Enterprise-D personnel were able to go aboard and examine some of its logs. The ship had become trapped in the field by a Menthar booby trap; the asteroids had been seeded with systems which absorbed energy from the ship's Lang cycle fusion engines and re-emitted it as harmful radiation. The ship had been unable to escape, and all of its crew had eventually been killed.

The Enterprise-D was also trapped in the field, but was able to free itself. The ship destroyed both the asteroids and the promellian battlecruiser to prevent any unwary travellers becoming likewise snared.