The Fallen Kingdom of Endara

The Kingdom of Endara, largely being made up of the city state of the same name, was once the seat of power and home for many fallen Sentinels of Afrid after their descent to the Material Plane. Although most Sentinels fell due to The Divine Exodus, there were a fair few that were not cast into the Underworld, finding themselves in the Material Plane instead. The first of them found a small village, which built itself into a city, then a city state as more and more arrived, growing significantly due to the Divine Exodus.
This would not last long; however, as, centuries before the raiders of The Valkan Isles would take the ruins of the city to form their new capital, disaster struck, causing the many fallen Sentinels to be struck with a sickness, which many historians believe to be linked to the disease that killed the majority of the vegetation and wildlife in The Cursed Isles. It is theorised that, due to being former servants of Afrid, the Goddess of Life, they were more affected by the curse, because of their connection to life itself.
Without their true immortality, and near divine power, they suffered greatly, causing those that survived to leave Endara to fall to ruins. To this day, much of Endara's architecture can be seen in Odessan, the capital of The Valkan Isles, with most of the building being restored rather obviously, given the differences in the Old Kingdom and the newer Valkans.