The Dracanomachi

The Great War. The First War Between Dragons. The Vengeance of the First Murder. The War of the Wyrms.
The Dracanomachi is a conflict, no, the conflict that defined our trajectory in this world. During its era-long length, the Old Empire was shattered and the alliance of man and Wyrm was forever changed.
It all started, as many things do in our early history, with the Great Wyrms. Tiamat and her brood had guided us for ages and then some, slowly aiding us in the development of human society. Social concepts and technology were introduced, but only wherever we were willing to take them. They established the Old Empire and aided in its growth and expansion. Tiamat herself saw fit to leave much of the world in our hands and the hands of her children, going off to find greater knowledge elsewhere. We, as a species, never saw her again in anything but our dreams. Perhaps it was for the best, for she did not have to see what followed.
Tiamat's daughter, Amunet, was murdered. Her siblings found her body in her nest, scales rent and wings broken. No man had any means or motivation to harm the dragons, on that the Wyrms agreed. After all, even with the technologies encouraged by the Wyrms which made putty of the rules of science that we ourselves are beholden to these days, the amount of resources that humanity would have had to expend to kill even one Wyrm, let alone a broodling of Tiamat, meant it had to be a kin killing.
Nothing of the sort had ever happened before, no Wyrm had ever died upon our world. It did not take long for the siblings to start making accusations towards each other. Amunet's grieving twin, Apep, was the first to make an accusation in the form of an assault upon her older brother Gungnir's hoard of magical items and artifacts. Shocked by the reckless action, he was driven from his hord and Apep melted everything she could get her hands on before giving chase. Gungnir, a rather jolly Wyrm if stories are to be believed, knew that his sister grieved, but also demanded some sort of censure. Some of what she had burned were artifacts created by their mother.
Humans started to stir, rallying behind the Wyrms that had helped them directly. Quetzalcoatl and his brood attempted to restore order, to introduce some sort of investigation. A human fleet, backed by Apep, challenged them too. She had decided that several of her siblings had conspired to kill her sister and any that attempted to hinder her search for what she thought as justice would be considered aiding and abetting her sister's murder. Quetzalcoatl, being the oldest child of Tiamat, would not be so easily cowed, but understood that trying to force the issue would only lead to greater fracturing amongst his siblings.
He relented, for a time, before it became apparent that Apep's grief and rage would not be expended with time or skirmish, he would gather his brood and attempt to assert control once more.
In the time he had withdrawn, however, his siblings had fractured even more, creating many internal factions backed by whole and sometimes multiple broods of Great Wyrms. Trying to bring one faction to heel merely made enemies with those that it was working with, and appeared to be allying with factions that had been enemies with the first, creating a dense web of enemies and allies that made trying to order in a piecemeal fashion impossible.
So the effort expanded, growing and mutating from a police action that sought to uncover a murderer to a war. A true war between the children of Tiamat, and humanity was all too eager to return the favor to the Wyrms that had helped them so.
The Dracanomachi would prove to be a truly apocalyptic conflict. Swathes of land were rendered uninhabitable by magical weapons that had never been used before, let alone used on such a massive scale. One that would define an Age of constant fighting and death.
The magnanimous Old Empire that had built itself upon ideals of equality and open dialogue turned its world-spanning resources towards war but could not agree with itself where those resources should go. Hundreds of factions, perhaps even thousands, formed, broke themselves upon the mill, and formed into something else. They were sometimes backed by Wyrms, other times not. Some even sought to remove the Dragons entirely, viewing them as the true threat.
Across Oshiore, the ruins of battlefields sit in layers under the dirt, and in the same way that one can see the history of a town by what remains in the layers beneath it, one can keep a definitive timeline by examining the weapons, insignias, and the number of skeletons found at each layer.
Almost no urban center survived the conflict, and new centers rose to act as barracks and command centers before being raised once more. Little of what existed before the war is known now due to the world-shaking magics employed by both humans and Wyrms. All we can do is attempt to piece together an approximate map of the world from scattered excerpts and quotes from writings from the time, often found in the deepest buried of Old Empire ruins.
The scale of death was massive, of course, but the true scale is unknowable without digging up every skeleton from the period and such an action wouldn't account for any of those who died and had little to no remains left after the fact. Wyrm fire rarely leaves behind a corpse, after all.
Some scholars argue that if the human ability to reproduce was not what it was, with an average of three children per pregnancy , that the damage done to our overall population would have been catastrophic to our health as a species.
As the war started with the Dragon's will, so it ended. It had long since stopped being about the murder of one Great Wyrm, now becoming about an endless stream of slights, insults, wounded egos, and idealism all veneered with the guise of righteous vengeance. Apep, her ebony eyes still streaming with tears, had long since quit the field and simply protected her sister's body where it fell with her magics and her soldiers (These soldiers would form the basis of the population for the City of Mourning). Finally, mercifully, Quetzalcoatl was able to reestablish control. There were no grand parades of victory, or real celebration at all. Only the sound of Dragon wings as Quetzalcoatl gathered up his siblings and all their scattered children to have a council once more, as they had done in the era before the war that had been long, even by the reckoning of the timeless dragons. The children of Tiamat, bar Amunet and Apep who could not be roused from her tears, admitted to their fault and reaffirmed their desire to help humanity.
Some suggested that they should be punished for their actions, but it was quickly realized that no one can punish a dragon. The humans were too hurt to truly do it, and to have another Wyrm punish them would only invite more conflict.
Thus we are here, vastly reduced from what we had built ourselves up to be with the dragon's knowledge and aid, yet now without much of that aid. The Wyrms, in their great wisdom, determined that their new approach would be far more hands-off than they and their mother had been in the past. They stabilized the world and set in motion their projects that would heal the worst of the worlds damage, but we were largely left to our own devices.
Even for all the blood and violence, Mother Tiamat still had not returned. Many felt great despair at that fact. Perhaps she was gone forever, or we were below her notice in reality.
Or perhaps she had abandoned us for our aid to the conflict between her progeny.

Conflict Type

War

Battlefield Type

Planetary

Start Date

1 of the Second Lunar Era

Ending Date

9597 of the Second Lunar Era

Conflict Result

The destruction of the Old Empire, and a virtual resetting of human progression.