World of Wu-Yu
The Iron Wars were a series of bitter conflicts in The Tathatan, lasting from BZY99 to BZY25.
In the second century BZY, nomadic Dwarves from the Tianshu mountains mastered iron working. Then, with their superior weapons and armor, they began laying waste to the urban agriculturalist Dwarves of the Tathatan. The Tianshu raiders destroyed Bara-xi in BZY104, and various Tianshu raider chiefs set themselves up as overlords. But the cities of the Tathatan resisted, and in BZY99 formed the Tathatan League, with the goal of throwing off Tianshu overlordship. Thus began the Iron Wars.
For three-fourths of a century, the two sides fought, ultimately resulting in stalemate. The Peace of Thauma, a treaty signed in BZY25 at a rebuilt Bara-xi, recognized the self-governing authority of city-states in the Tathatan and Tianshu raider kingdoms in the Iron Forest.
The conclusion of the wars had significant consequences. The Tathatan city-states found themselves with an enormous military and no foe left to fight. At that time, the East was severely depopulated due to the spread of Goat Plague. So the Tathatan city-states chose to strike east. They crossed the Tianshu mountains and began a campaign that ultimately led to the founding of The Empire.