The Eastern Crusade was a war between the necromancer Belet-Shuthnir and a coalition between the local city-states of the eastern Chaska Sea, Thadrian and Hellean states, and a variety of religious orders.
In Y8431*, the powerful necromancer Belet-Shuthnir took control of Anaharath, a city north of Tamkaranu. After consolidating power, she began an unholy war against the other polities in the region, quickly conquering south to Aradet and Gath Padalla, north up to the River Qes, and east to the frontier of the Arrajan Wilds.
After years of study and terrible deeds, in Y8440* Belet-Shuthnir succeeded in her goal of attaining lichdom. Powers around the Chaska began to take notice and draft plans to defeat the new evil. The Eastern Crusade began in Y8446* as a direct result, fought by an alliance between local cities, Thadrian and Hellean states, and a number of religious orders. Though slow and extremely costly, the crusaders were eventually successful in pushing the necromancer back to her capital in Anaharath. In the final battle outside the city in Y8452*, half the remaining allied crusader force was flash-petrified, where they remain outside of the city today at the Field of the Victorious. With her soul cage destroyed and scattered, the body of Belet-Shuthnir was entombed and warded deep below Anaharath to seal it away, where she remains today. Devastated by almost fifteen years of war, Tamkaranu took decades to fully recover from the crusade.
The modern state of Tamkaranu exists in large part due to the Eastern Crusade. After Belet-Shuthnir and her undead armies were destroyed at the conclusion of the war, many of the crusaders from elsewhere around the Chaska Sea remained in the region. In an effort to hold together their fragmenting alliance, one faction of the crusaders convened a summit to determine the fate of the war-torn lands. They selected one of their own, Tullus Antar, to lead their new realm from the city of Nindara. The kingdom of which Antar was the first monarch would last for nearly a millennia before its eventual collapse gave rise to the modern nation of Tamkaranu.