Chakatai

The Chakatai are a very old and refined civilization: it was already ancient when the Westlanders were still nothing but humble shepherds (over 1,000 years ago).
Unlike other ancient civilizations from that time which eventually collapsed, such as the Kothraki Empire, The Chakatai have endured across all the millennia to the present day, making it one of the richest and most advanced societies in the known world.
The Chakatai live mainly live inside their gargantuan wall, separating the Eastern Deathlands from Kothrak.
Even the ruins of fallen cities in The Great Wall dwarf the largest cities in the Western Continent.
Its nobles are said to live in houses of solid silver, and feast on Giant Lizard meat powdered with exotic salts and spices from beyond the Eastern Deathlands - if the stories are true.
The religion of the Chakatai includes elements from all four pantheons but is focused around two primary deities: Nestal and Nahos.
Few from the Western Continent have ever traveled all the way to the Great Wall of the Chakatai, though a handful of adventurers have made the long journey.
While a few Westerners have traveled to the Great Wall and while it is known to be a real location, most people know very little about the area, and it is still semi-legendary to people living in the Western Continent (much moreso than Dunreath, but not nearly as much as feared Eastern Deathlands).
Even the greatest historians in history only know a basic outline of its history and culture - in part because Chakatai scholars greatly prize their delicate, millennia-old historical scrolls, so they don't share them with those who live beyond the Great Wall.
The Chakatai are one of the oldest civilizations in the known world, extending at least as far back as the Black Ages 2,000 years ago.
Several different civilizations actually have rival claims to be the eldest, particularly the Chakatai, Dunreath, and the Kothraki.
Of these, only the Kothraki possesses a written record extending far enough back to serve as reliable proof that it was eldest. The Kothraki actually originated before the Black Ages, and was still young at the time of the "cataclysm".
The Chakatai claim that they had an even older empire for many thousands of years before that, during the Early Ages, but that the Great Wall was destroyed during the Black Ages and had to be rebuilt. The tales of this Great Empire of the Early World (as it is known) are grandiose and apparently mostly legend, filled with emperors who lived for centuries and warred with the gods.
Still, only a few generations separated the confirmed founding of both; The Kothraki Empire slightly before the Black Ages and Great Wall of the Chakatai slightly after - yet the Kothraki Empire was destroyed 500 years ago by the rising Men of Dunreath. In contrast, the Great Wall of the Chakatai is by far the oldest continuous civilization in the world, both at present and throughout recorded history, with a culture and accurately transmitted historical record stretching back 2,000 years, to the end of the Black Ages. In comparison, the Kothraki Empire lasted about 750 years.
The Great Wall of the Chakatai is therefore extremely advanced, because while it has had its share of civil wars, its society never truly collapsed in the way that the Kothraki Empire did after the rise of the Men of Dunreath, or experienced an effect like the Great Freeze had on the north of the Western Continent.
For many millennia, the country has indeed been ruled by a series of divine god-emperors, but in recent centuries their power has greatly diminished, extending no further than the boundaries of the Great Wall. The real power has come to reside in strong regional princedoms, numbering about a hundred or so but nominally all part of the same wall. The Great Wall of Chakatai's original capital city after the Black Ages was Jingbei, a major port on the southern coast at the wall. The capital shifted around to different cities over the millennia depending on which dynasty was in power, and at times was located in the cities of Shaihang and Zhenshen. In the present day, the capital is once again located in the ancient city of Jingbei, with the god-emperor living in a palace nearly the size of Dunreath, a heavily guarded city-within-a-city.
The Great Wall of the Chakatai have a long and extensive history dating back 2,000 years, but only a vague outline of it is known to the greatest historians of the West. Since the Black Ages, The Chakatai have been ruled by eleven different dynasties of emperors: the longest lasted six centuries, the shortest only a single century. Sometimes the transitions between dynasties were peaceful, other times they were violent. On three occasions, the fall of one dynasty did not immediately lead to the establishment of a new one, but led to prolonged periods of civil war and anarchy, the longest of which lasted over a century, but even this was never enough to outright destroy the literary record, knowledge, and continuous history of Chakatai civilization.
Each dynasty took its name from the last name of the ruling emperor, i.e. the current dynasty are the "Zhougang Emperors". The exact order of Chakatai dynasties is unclear:
Jintian Emperors - ruled from Jingbei.
Zhaohang Emperors - ruled from Jingbei.
Du-cheng Emperors - ruled from Jingbei. Considered a rich golden age. To display their prosperity, all the furnishings in the imperial palace were made of solid silver, even the chamber pots.
Housuz Emperors - perhaps the most infamous dynasty. They greatly expanded the empire and strengthened central power. Some were great statesmen, others ruthless but competent, and still others ruthless and incompetent. They moved the capital from Jingbai to Shaihang (which was left in ruins after their dynasty ended). Many members of the dynasty were wicked and cruel, though the last emperor ruled wisely and well for twenty years. He survived the numerous assassinations within the imperial family by pretending to be a lackwit struck with an affliction that made him limp and drool when he tried to speak. A famous historical drama recounts his unlikely rise to the throne. The Housuz Emperors reigned about 750 years ago, and warred against the Outsider Clans to the north of the wall.
Jing-nan Emperors - ruled from Jingbei. Their reign was a golden age of peace and prosperity, with eight emperors ruling for 120 good years. While each of them had children before taking the throne, they were each voluntarily castrated when they became emperor, so as not to be distracted from matters of state.
Han-wu emperors - at least seven emperors under which the Chakatai are said to have achieved the height of their power. They also ruled from Jingbei. They conquered and held large swathes of land beyond the wall, and lands as far away as Dunreath and the Kothraki paid them tribute. They traded with the West, unlike most other dynasties.
An'Xi Emperors - moved the capital to the western end of the wall to Zhenshen, and reinforced the western borders against the Outsider Clans in the North of the Eastern Deathlands.
Zhouzheng Emperors - moved the capital back east to Jingbei, and reinforced the eastern borders against monsters from the heart of the Eastern Deathlands.
Daoqing Emperors - died out 200 years ago. Traded with the Men of Dunreath, who were then also at the height of their power. Chian Shek-Kai, the third emperor of the dynasty, married a Dunreath noblewoman and kept a sand dragon at his court.
Zhougang Emperors - the current dynasty, who rule from Jingbei. Relatively weak, with the regional princedoms rising in power. Zhenshen broke free from their control about 10 years ago.
The current emperor is Bo Ning, the 16th Zhougang Emperor. However, a general on the southern frontiers named Binhar Yangshen at the garrison city called Menxia has declared himself the first "Yangshen Emperor", and is slowly gathering his strength.
Meanwhile, far to the east of even distant Deathlands, the vaguest of rumors and black legends tell of the strange city of Nailad, ruled by "Zhougang" - allegedly the last of the Zhougang Emperors, overthrown and exiled for practicing twisted dark arts. According to the stories, the Zhougang Emperor has managed to prolong his life for over 200 years through arcane and unspeakable magic rituals, and he is biding his time in Nailad until the day when he will attempt to reclaim the Great Wall of the Chakatai. Others say that this is just a story told inside the Wall to frighten misbehaving children.