The Great Light that was a prelude to the dark age
The era of darkness after the cataclysm. Notable for being a time of minimal cultural, technological and scientific growth. And even a time of Cultural regression into societies mirroring those of feudal Europe during the dark ages, albeit on a larger, global scale.
The EUS seeks to own more of the galaxy.
Formed out of necessity during a great cataclysm in Earth's past, the governments and powerful families of old united to fix the problems of earth, founding the EUS.
An ambitious undertaking seeking to establish a capital city on Mars, similar though smaller to Severance City, the sprawling metropolis on Earth.
A long dark period of unrest in the Mariner Valley due to Earthborn control of the fiercly independent Martian culture.
The time of great tension prior to the Great Solar War. During this time; the SDA was formed and great leaps in technology were seen, the EUS fleet was expanded greatly, and Mars unites behind the Mariner Valley Citizen Effort, soon to be known throughout Sol as the ruthless Martian Resistance Force or more commonly the MRF.
The SDA is formed as a research and development organization to supply the EUS with newer and stronger Military Technology.
Though not an official military action, many view this as the inciting incident of war. The Sky-Docks of Deimos and Phobos are thrown into chaos following Martian declaration of indepence, Earthborn humans try to escape in a frenzy. Martians, swelling with planetary pride, antagonize EUS soldiers and the fearful Earthborn. The MRF uses this as an opportunity.