Marg-Rom was a native of the city of Kandor on the planet, Krypton in the Kryptonian year 9873. He worked as an assistant to the great architect known as Gam-El. Following the Last War, Marg-Rom and Gam-El traveled to the ruins of Kryptonopolis on the continental wastelands of Lurvan. Marg-Rom worked diligently alongside Gam-El in restoring Kryptonopolis to its former glory and establishing it as the planet's new capital city. He helped to secure financial backing from the Kryptonian Science Council and by 9874, construction of the new city was complete.

  • This version of Marg-Rom (Earth-One), including all history and corresponding appearances, was erased from existence following the collapse of the original Multiverse in the 1985–86 Crisis on Infinite Earths limited series. Even though versions of the character may have since appeared, this information does not apply to those versions.
  • Marg-Rom presumably passed away long before the destruction of Krypton.