Most of Yimir’s history has been dominated by massive wars between the chromatic and metallic dragons, with Tiamat and Bahamut on their respective sides. Mortal races were typically ignored and their deaths were treated as unfortunate collateral damage by the metallics, while the chromatics would use the mortal races as cannon fodder. Still, some mortal races were able to build independent empires capable of surviving the wars, chiefly humanity.
The majority of humans became unified in modern-day Cotralis and formed a very strong force capable of surviving without being controlled by the chromatics, though the population in the northern wastes was still seperate. The human empires generally were tacit allies of the metallics, and were afforded some measure of protection. It was during these conflicts that a large population of elves went underground to escape the constant warfare, eventually becoming Grey Elves.
2000 years ago, the everlasting stalemate between the metallic and chromatic dragons was broken, leaving the metallic dragons running for their lives. Tiamat’s chromatic dragons were relentless, systematically slaughtering any metallic they could find as well as those with metallic bloodlines. Bahamut, the patron god of the metallics, ceased direct operation on Yimir shortly afterward. Chromatic dragons often estimate that all metallic dragons and bloodlines were completely purged 1000 years ago. The chromatic dragons, however triumphant, had lost a massive quantity of population mass, and needed a few generations to regroup. Tiamat mysteriously ceased to interfere after this victory, and ceased all activity on Yimir, much to the chromatics’ surprise. During this purge, humanity experienced incredible growth, and plans were made to field a massive army capable of wiping out the chromatics. Meanwhile, the Grey Elves emerged from the mountains of Oslund and began building the foundations of most of the above-ground cities of Oslund.
Following the metallic defeat, peace accidentally occurred as the chromatics needed time to rebuild their numbers, as they knew the human empire was far too powerful to directly attack in their weakened state.