The Liao dynasty (; traditional Chinese: 遼朝; simplified Chinese: 辽朝; pinyin: Liáo cháo), also known as the Khitan State (Mos diau-d kitai huldʒi gur), officially the Great Liao (Chinese: 大遼; pinyin: Dà Liáo), was a Khitan-led imperial dynasty of China and empire ruled by the Yelü clan that existed between 916 and 1125. Founded around the time of the collapse of the Tang dynasty, at its greatest extent it ruled over Manchuria, the Mongolian Plateau, the northern part of the Korean Peninsula, southern portions of Siberia, and the northern tip of the North China Plain.
The dynasty rose from the consolidation of power among the Khitans in the 8th century and their expansionist campaigns in the latter half of the 9th century. Eventually the Yila chieftain, Abaoji, became the leader of the Khitans and proclaimed a Chinese-style dynastic state in 916. The Liao dynasty launched multiple military campaigns against neighboring states and peoples including the Kumo Xi, Shiwei, Tatars, Zubu, Khongirad, Balhae, Goryeo, Later Tang, and the Song dynasty. Its conquests include the Sixteen Prefectures (including present-day Beijing and part of Hebei) by fueling a proxy war that led to the collapse of the Later Tang (923–936). In 1004, the Liao launched an expedition against the Northern Song dynasty. After heavy fighting and large casualties between the two empires, both sides worked out the Chanyuan Treaty. Through the treaty, the Liao forced the Northern Song to recognize them as peers and heralded an era of peace and stability between the two powers that lasted approximately 120 years. It was the first state to control all of Manchuria.
The Liao dynasty was destroyed by the Jurchen-led Jin dynasty in 1125 with the capture of the Emperor Tianzuo of Liao. However, the remaining Liao loyalists, led by Yelü Dashi (who would become Emperor Dezong), established the Western Liao dynasty (or Qara Khitai), which ruled over parts of Central Asia for almost a century before being conquered by the Mongol Empire. Although cultural achievements associated with the Liao dynasty are considerable, and a number of various statuary and other artifacts exist in museums and other collections, major questions remain over the exact nature and extent of the influence of the Liao culture upon subsequent developments, such as the musical and theatrical arts.
The Great Khitan State (Chinese: 大契丹; pinyin: Dà Qìdān) was founded in 907 by Abaoji (Emperor Taizu of Liao). In 938 or 947 Abaoji's successor, Emperor Taizong of Liao, officially renamed the dynasty as Great Liao (Chinese: 大遼; pinyin: Dà Liáo). This was probably due to the inclusion of non-Khitan peoples in the state. The name was changed back to Great Khitan in 983 during the reign of the Emperor Shengzong of Liao due to a re-assertion of Khitan identity. In 1066 Emperor Daozong of Liao reintroduced the dynastic name Great Liao, and the title remained in official use until the dynasty's collapse. Both Great Khitan and Great Liao enjoyed about 100 years of usage.
In the Khitan script, the state's name included the words Khitan and Liao, but their order was reversed depending on which took precedence. When the state was called Great Khitan in Chinese, the corresponding Khitan language name was Great Khitan Liao (Great Qidun Hura), whereas when it was known as Great Liao in Chinese, the corresponding Khitan name was Great Liao Khitan (Great Hura Qidun). The full name in the Khitan language was thus either Great Central Khitan Liao State (Great Tiaudu Qidi Xura Guren) or Great Central Liao Khitan State (Great Tiaudu Xura Qidi Guren). It is uncertain what the word Liao (Hura) actually meant in the Khitan language. There are several theories for its possible meaning including black, broad, country, the Liao River, or simply a prestigious term whose original meaning had been lost.
In 1124 the successor state established by Yelü Dashi in the Western Regions also officially adopted the dynastic name Great Liao. In historiography, however, this regime is more commonly called the Western Liao or Qara Khitai. The Qara Khitans used neither Western Liao or Qara Khitai to refer to themselves. They regarded themselves as the legitimate continuation of the Liao dynasty and continued to use the Khitan name, Great Liao Khitan (Great Liao in Chinese), as their self-designation. Western Liao is a Chinese designation and Qara Khitai is a Turko-Mongol term. Qara Khitai cannot be found in any Muslim sources before the Mongol invasions, after which Turko-Mongol speakers mistook the word for Liao (Hura) as qara (black). Muslim historians initially referred to the state as Khitai, which may have come from the Uyghur form, in which the final -n or -ń became -y. They adopted the name Qara Khitai after the Mongol invasions.
Due to the dominance of the Khitans during the Liao dynasty in Northeast China and Mongolia, and later the Qara Khitai in Central Asia where they were seen as Chinese, the term Khitai came to mean China to people near them in Central Asia, Russia, and northwestern China. The name was then introduced to medieval Europe via Islamic and Russian sources, and became Cathay. In the modern era, words related to Khitai are still used as a name for China by Turkic peoples, such as the Uyghurs in China's Xinjiang region and the Kazakhs of Kazakhstan and areas adjoining it, and by some Slavic peoples, such as the Russians and Bulgarians.
The Khitan imperial family used two different names for their surname, Yila and Yelü. Yila (Ila) was probably an older term and meant stallion, related to messenger, standard-bearer, warrior. Yelü (Yarud) was adopted at a later point, possibly in the 930s, and is related to the Khitan adjective for flourishing, prosperous.
The earliest reference to a Khitan state is found in the Book of Wei, a history of the Northern Wei dynasty (386–534) that was completed in 554. Several books written after 554 mention the Khitans being active during the late third and early fourth centuries. The Book of Jin (648) mentions the Khitans in the section covering the reign of Murong Sheng (398–401). The Samguk Sagi (1145) mentions a Khitan raid taking place in 378.
It is generally believed that the Khitans emerged from the Yuwen branch of the Xianbei people. Following a defeat at the hands of another branch of the Xianbei in 345, the Yuwen split into three tribes, one of which was called the Kumo Xi. In 388 the Kumo Xi itself split, with one group remaining under the name Kumo Xi and the other group becoming the Khitans. This view is partially backed up by the Book of Wei, which describes the Khitans originating from the Xianbei. Beginning in the Song dynasty, some Chinese scholars suggested that the Khitans might have descended from the Xiongnu people. While modern historians have rejected the idea that the Khitan were solely Xiongnu in origin, there is some support for the claim that they are of mixed Xianbei and Xiongnu origin. Beginning with Rashid-al-Din Hamadani in the fourteenth century, several scholars have theorized that the Khitans were Mongolic in origin, and in the late 19th century, Western scholars made the claim that the Khitans were Tungusic in origin (modern linguistic analysis has discredited this claim).
After splitting from the Yuwen, the Khitans and Kumo Xi fled to the region of Songmo (modern southern Hexigten Banner and western Ongniud Banner). According to the New Book of Tang, the territory of the Khitans rested on what is now the area south of Xar Moron River and east of the Laoha. The Khitans then faced a joint invasion by the Rouran Khaganate and Goguryeo, which caused them to migrate south to the east of Bailang River (modern Daling River).
By the time the Book of Wei was written in 554, the Khitans had formed a state in what is now China's Jilin and Liaoning Provinces. The Khitans suffered a series of military defeats to other nomadic groups in the region, as well as to the Northern Qi (550–577) and Sui (589–618) dynasties. Khitan tribes at various times fell under the influence of the Uighurs and Sui and Tang dynasties. In the Book of Sui (Volume 84), the Khitan are described as "bellicose in plundering and raiding borders" and "the most uncourteous and arrogant among all barbarians". According to the History of Liao, the Khitans were nomads who migrated according to the season. They depended on horses for their livelihood and let them graze openly while their men were demobilized. Their men drank kumiss and practiced archery to hunt for their daily needs. Due to their way of life, they often had the upper hand in military affairs.