The history behind the Mobile Core units, which would become the predecessor to the Mobile Suit.
About this creation
Following what would be called the "Terror Crisis" and the "Economical Crisis" of the 21st Century AD, the science and technology of Robotics advanced in leaps and bounds during the 22nd Century AD. New civilian construction suits evolved and aided Humanity in the colonization of space with the new Space Colonies.
The various militaries of the Earth would later adapt this technology in the early 23rd Century and create units called "Mobile Cores." These new units were used to supplement conventional ground forces in both offensive maneuvers and base defenses. The first time that an offensive force comprised primarily of Mobile Cores was used on the battlefield was during the Neo-Soviet Union invasion of Europe. This invasion changed the current doctrine of war and led to the rapid development and deployment of more advance Mobile Core units throughout the various world superpowers.
The term "Mobile Core" came from putting together "Mobile Suit" and "Armored Core". I am still trying to figure out how "Mobile Core" relates to mecha, especially the mecha of this genre, but it works somehow.
I also wanted to create what would come before the famed Mobile Suits. In every Gundam series, you see the Mobile Suits and hear that they were developed from something else. The question that I always had was what were the mechs/robots/whatever that Mobile Suits were derived from. So I answered my own question and made my own design/idea, and thus the Mobile Core unit was born.