The Sack of Chyowo, taking place in 2259 KS, took place after a war between Chyowo Clan and Yerzhay Clan.
War between ʈ͡ʂʷɥɔwɔ and ɥəʐəɥ was nothing new - like all Wajahe, there was a history of border skirmishes and minor battles, that never amounted to much. This war started out similarly, with a blood feud over neighboring settlements across the border escalating to a larger border clash. However, the central battle across those border plains would end up being a decisive clash.
During the border clash, ʈ͡ʂʷɥɔwɔ decided to deploy their armies in a spread out line, while ʈ͡ʂʷɥɔwɔ picked a normal arrangement. The hope for ʈ͡ʂʷɥɔwɔ was quick and easy flanking, but the ɥəʐəɥ lancers quickly chased away the chariots and javelin cavalry, then pushed forward, leading to a quick rout. This was followed up by a series of battles in which the entire ʈ͡ʂʷɥɔwɔ army was killed or captured.
With this decisive victory, ɥəʐəɥ was finally able to escalate the border conflict, and ʈ͡ʂʷɥɔwɔ, after a few insignificant battles, was eventually defeated and conquered outright. The city was sacked, but did not suffer significant infrastructural damage, and remained an important regional site.
After this war, the 4th Dynasty state would emerge, centered originally in the ɥəʐəɥ clan, though it would very quickly become a cooperative endeavor by the ɥəʐəɥ and ʈ͡ʂʷɥɔwɔ.