Zeon used the base as a defensive location as well as to develop mobile suits. Pezun produced mobile suits for the Zeon war effort, in particular the MS-10 Pezun Dowadge that was named after it.
After the war, Pezun was occupied by the Earth Federation’s Mobile Suit Instructor’s Coprs under the Titans. When the Titans was disbanded by the Federation in UC 0088, the Instructor’s Corps seized Pezun in a military coup and declared themselves the New Desides.
The Federation sent the Task Force Alpha to quell the rebellion. The New Desides forces were pushed back and were forced to abandon the base on 12 March UC 0088. The rebels detonated nuclear warheads to destroy Pezun and damage the Federation fleet.