In the years leading up to the One Year War the Zimmad Company was among the companies trying to win the military contract with the Principality of Zeon, which would be provided to whichever company developed a working prototype of a next generation mobile weapon. The Zimmad Company, alongside rival Zeonic Company, developed and produced a mobile suit prototype, the EMS-04 Zudah and the MS-04 Prototype Zaku respectively. Though Zimmad's Zudah mobile suit design had a high performance rating it had a fatal defect in the propulsion system and consequently lost out to the Zaku.
To compete with Zeonic's MS-07B Gouf Zimmand Company created a limited mass production of MS-08TX Efreet. The production would be halted in favor of newer and more revolutionary designs like the MS-09 Dom. Zimmad eventually triumphs over its longtime rival Zeonic with the success of their Dom line of mobile suits. The MS-09R Rick Dom is chosen to succeed the Zaku II as the Principality's main space combat mobile suit, and its probable that the MS-09 Dom would have become the main ground mobile suit if Zeon hadn't been pushed off the Earth. However, its next design, the YMS-15 Gyan, is rejected in favor of Zeonic's MS-14 Gelgoog. After the end of the One Year War, Zimmad devotes itself to maintaining the equipment of the Republic of Zeon's military forces. After the One Year War, the company, along with rivals Zeonic and MIP, merges with Anaheim Electronics.
- Jean Luc Duvall - An officer in the Principality Forces after working as a test pilot at Zimmad for 12 years.