Hold up...
After said civil war occurred and the Ancients fractured, all that was left were ruins and small villages. There are no large cities and only limited contact and trade before the game.
In other words, advanced civilization collapsed. While there wasn't a nuclear war, this scenario seems to resemble the Bronze Age Collapse, though that involved not one civilization but a sophisticated and interconnected network of many states, and its causes were more complex than civil war.
In the late Bronze age, civilization in the near east basically ceased. Most large states collapsed, cities were abandoned, and trade, technology and even the written word were lost.
In the span of half a century, literally thousands of years of progress and stability were undone, and it took hundreds of years to recover from, by which time knowledge of much of the Bronze Age was forgotten or mythologized.
Extra Credits di...