The Liao Kingdom, originally called Khitan, was later named "Liao" because its people lived along the upper reaches of the Liao River. In the Khitan language, "Khitan" means wrought iron. Emperor Taizong of the Tang Dynasty once established the Songmo Protectorate in Khitan territory to govern the local Khitan people. During the late Tang Dynasty, as the Central Plains fell into chaos, Yelü Abaoji, the leader of the Khitan's Diela tribe, took the opportunity to unify the various Khitan tribes and founded the Liao Kingdom.
Yelü Abaoji came from a distinguished lineage; from his great-great-grandfather all the way to his father, every generation held military command within the Khitan tribal confederation, with a status second only to the confederation's chieftain—truly a position of being beneath one person yet above ten thousand others.
When Yelü Abaoji was born, the nobles of various tribes were all engaged in open and covert struggles to become the leader of the Khitan tribal alliance, and Abaoji's grandfather died in this political war.
Yelü Abaoji was exceptionally intelligent from a young age and deeply loved by his grandmother. As an adult, he grew tall and robust, possessing great physical strength and martial skills. More importantly, he harbored a grand ambition to unite all the Khitan tribes. To achieve this goal, the young Abaoji led a military force left by his uncle and embarked on a campaign of conquest across the region. His efforts paid off, and with his remarkable military achievements, Yelü Abaoji finally ascended to the position of tribal alliance leader in 907 AD.
At that time, the leader of the tribal alliance was called the Khan, and within the Khitan people there was a rule: each Khan's term in office was limited to three years, and when the time was up, a new Khan had to be elected immediately. However, Abaoji refused to step down after three years because he wanted to emulate the Central Plains and establish a hereditary succession system. Many nobles within the Yelü clan had originally hoped to be elected Khan, but now their hopes were dashed, and they naturally harbored resentment toward Abaoji, leading them to launch three consecutive rebellions. Since these rebels were all brothers from Abaoji's own clan, this series of uprisings became known as the "Revolt of the Brothers."
After Abaoji successfully quelled a rebellion from his own tribe, the situation within the tribe stabilized, and the next challenge he faced came from other tribes. Since the remaining seven tribes united and were powerful, Abaoji chose to temporarily agree to abdicate. The earlier rebellion and its suppression had severely impacted the tribe's economic development, leaving the people without even horses to ride when traveling, so Abaoji took this opportunity to rest and recover.
Abaoji's wife, Empress Shulü, was an exceptionally wise and remarkable woman. She advised her husband to use the pretext of a banquet to lure the chieftains of the other tribes, and once they were all drunk, seize the opportunity to capture them all at once. In this way, Abaoji's internal and external troubles were completely resolved. In 916 AD, Yelü Abaoji established the Liao Dynasty and proclaimed himself emperor, historically known as Emperor Taizu of Liao.
To expand his territory, after ascending the throne, Yelü Abaoji continuously waged campaigns to the south and north. Although the process was not smooth, his outstanding military talent and fierce command in battle allowed the Liao Dynasty's territory to keep expanding.
After Yelü Abaoji died, his second son Yelü Deguang succeeded him, historically known as Emperor Taizong of Liao. Yelü Abaoji had three sons in total, and his favorites were the eldest, Yelü Bei, and the second son, Yelü Deguang. Early in the founding of the Liao state, Yelü Bei had already been appointed crown prince. However, Yelü Deguang, having accompanied his father on military campaigns for years, earned remarkable achievements in battle, something his elder brother Yelü Bei clearly could not match. Additionally, Yelü Bei's strong admiration for Han Chinese culture displeased their mother, Empress Dowager Shulü. Combining these factors, their mother firmly sided with the second son, Yelü Deguang, in the succession to the throne.
Meanwhile, Yelü Abaoji had always held high hopes for this son who had become the supreme commander of the empire's armies at the age of twenty, and Yelü Deguang indeed did not disappoint his father's expectations. After ascending the throne, Yelü Deguang vigorously developed the Liao Dynasty's politics and economy. Building upon the official system established by Abaoji, he introduced the Later Jin Dynasty's Han Chinese bureaucratic structure into the Liao, allowing the Liao's official system to partially adopt Han Chinese characteristics while still preserving its own ethnic identity. Since the Liao's inhabitants belonged to many different ethnic groups, Yelü Deguang established separate Southern and Northern administrative systems. The Northern system governed the Khitan and other nomadic peoples, while the Southern system administered the Han Chinese within the territory.
During the reign of Emperor Taizong of Liao, the Liao state entered a period of prosperity, with its territory continuing to expand; the Sixteen Prefectures of Youyun were incorporated into Liao's domain during this time, and its influence even extended into the Central Plains. At that time, agricultural production within the Liao state developed considerably, while the Khitan ethnic culture also advanced rapidly.
During this period, various northern ethnic groups interacted closely in politics, economy, and culture, learning from each other and advancing together.
Both father and son, Yelü Abaoji and Yelü Deguang, died on the road while returning from military campaigns. Yelü Abaoji succumbed to illness, but his son Yelü Deguang died from excessive indulgence in pleasure. When Yelü Deguang died, it was the height of summer, and to prevent his corpse from decomposing beyond recognition before it could be transported back to the Liao Kingdom, his ministers had to remove his internal organs and preserve the body with a large amount of salt. This essentially turned Yelü Deguang's corpse into a mummy, a practice absolutely unique among Chinese emperors throughout history.