Originally the western portion of the Torphan Empire, the area now known as East Torphan was conquered by the Cedonians in a prolonged war. The peace agreement with the Torphan Empire gave the Cedonians a new county of Imperial East Torphan, and the source of a bone of contnention between the two empires for hundreds of years.
With the fall of the Cedonian Empire after the goblin Ice Demons ransacked the area, the cities of the Imperial county declared their independence. This was shortlived however. The Torphan Empire invaded the southwestern cities and crushed all opposition. In horror, the northern cities banded together to form a protective alliance, now known as East Torphan. The eastern cities formed the new realm of Larasia for the same reason (though that was later conquered by the Parglug).
The Torphan Empire claims East Torphan to this day, and the border between the two nations is heavily defended on both sides.