andong.over-blog.com :  History of the Far East

In 926, when Khitan tribes finally engulfed Parhae and brought the power of the steppe nomads ever closer to Koryo's northern frontier, Wang Kon initiated plans to reconquer the old Koguryo territory of T'aebong (The Later Three Kingdoms). He stationed a large military garrison force in Pyongyang under the command of his cousin, General Wang Sing-nyom. Pyongyang, once a vibrant city that served as a frontier outpost for the former Silla kingdom, had seriously declined after the fall of Koguryo. Its small population lived in dilapidated buildings among the ruins of the city's old fortifications. Pyongyang's real value however, lay in the fact that it sat on the banks of the Taedong River as a strategic frontier

The reorganization and strengthening of Koryo's central government may also have been prompted by the rising strength of Koryo's neighbors to the north and west. For twenty years Koryo shared a common frontier border across the northern half of the peninsula with the powerful nomadic Khitan empire. In their capital city at Liaoyang on the Liao River near modern Mukden the Khitan developed a governing structure very similar to a regular Chinese-style state. In 946, less than a year after Chongjong took the Koryo throne, the Khitan announced the formation of the Liao Dynasty and prepared to satisfy their ambition to expand their domain southward. First they would conquer the territory north of Korea, then take Koryo itself. Fully aware of Parhae's fate and suspicious of Khitan intentions, Koryo intensified preparations for a military defense against an expected invasion from the north along Koryo's frontier.

King Chongjong never moved his capital from Kaesong to Pyongyang. Over a two year period Chongjong raised an army of about 300,000 men from the private armies of the land barons and brought them together under control of the central government as the Resplendent Army, Kwanggun. The creation of such a large standing army bolstered the muscle needed by the civil bureaucracy to consolidate the central government's power in Kaesong. With a number of garrison forts already in place north of the Ch'ongch'on River, the Resplendent Army also afforded Koryo the opportunity to pursue a policy of northward expansion toward the Yalu River.

http://koreanhistoryproject.org/Ket/C04/E0404.htm

Refugees from the earlier destruction of the Kingdom of Parhae by the Khitan settled in a mountainous region along the middle reaches of the Yalu River where they formed the small kingdom of Chongan. Squeezed between the Liao Dynasty on the north and Koryo on the south, Chongan established connections with the Jurchen nomads of eastern Manchuria and used them to establish and maintain communications with Song China. For years Jurchen envoys traveled down the Yalu River and crossed the Gulf of Bo Hai to China, carrying on both trade and diplomacy with the Song court in Kaifeng. In addition, both Chongan and Koryo shipped military horses to the Song along this same route. The people of Chongan took an actively hostile stance against the Khitan and their link with the Song Chinese greatly annoyed the Liao state. The Khitan moved to end such provocative behavior in 983 by launching a series of major assaults against the Jurchen tribes in eastern Manchuria. Within two years, Khitan troops occupied Chongan territory and the Tongga River basin.

Although the Khitan focused their attacks against Song China, they could not erase their deep apprehensions about Koryo's intentions in the south. The Liao state increasingly feared an alliance between Song China and Koryo as a direct threat to its own safety. As tension along Koryo's northern frontier heightened, the Khitan emperor tried to counter the possibility of being outflanked by once again trying to establish friendly relations with the Koryo government. Once again he was refused. Faced with Koryo's refusal to establish relations and its continued economic trade relations with China, Liao officials concluded that the only reasonable alternative left was to invade Koryo and conquer it outright. The Khitan launched their third major assault against the Jurchen in the Chongan territories along the mid-reaches of the Yalu River in 989

This time they occupied the territory in depth and constructed three major fortresses along the north bank of the Yalu River. Two years later, the Khitan completed construction of a large fortress at Naewon-song on the lower Yalu River near modern Kumdong-do, and effectively cut the only communication link between Chongan, the Jurchen and Song China. Ever wary of Khitan intentions, Koryo responded by building its own fortifications along the south bank of the Yalu River.

In late August 993, Koryo intelligence sources along the frontier learned of an impending Khitan invasion. Beacon fires lit the ridge tops between the Yalu River and the capital in Kaesong warning of the threat. King Songjong quickly mobilized the military and divided his forces into three army groups to take up defensive positions in the northwest. Advanced units of the Koryo army marched northwestward from their headquarters near modern Anju on the south bank of the Ch'ongch'on River. The seriousness of the situation compelled King Songjong to travel from the capital to Pyongyang to personally direct operations. That October, a massive Khitan army said to number nearly 800,000 men under the command of General Xiao Sunning swarmed out of Liao from the Naewon-song Fortress and surged across the Yalu River into Koryo. Waves of Khitan warriors swept across the river and fanned out over the countryside. They overran towns and farmlands, butchered whole populations, and laid waste to Koryo culture by razing national shrines, libraries, and monuments.

In bloody seesaw warfare, the fierce resistance of Koryo soldiers at first slowed, then considerably hampered the Khitan advance at the city of Pongsan-gun. As they had done with the Chinese, Koryo's army never surrendered. It stood firm against frontal attacks, broke to retreat and lay ambushes, and launched flanking attacks against the Khitan. Koryo warriors finally halted Xiao Sunning's army at the Ch'ongch'on River. In the face of such quick and determined resistance, the Khitan decided that further attempts to conquer the entire peninsula would be far too costly, and sought instead to negotiate a settlement with Koryo.

What the Khitan could not take on the battlefield with arms, they tried to steal with words. Without a hint of contrition or humility, General Xiao Sunning demanded the surrender of the former territory of Parhae to Emperor Shengzong. He demanded that Koryo sever its relations with Song China and, in the boldest demand of all, that King Songjong accept vassal status under the Liao emperor and pay a set annual tribute to the Liao state. Instead of responding with a unified voice and rejecting General Xiao's demands outright, the Khitan ultimatum quickly became the topic of heated debate in the royal court at Kaesong. Government officials on one side believed that acceding to General Xiao would prevent further Khitan incursions and they urged the court to appease the Liao emperor. Many of the senior military commanders who had recently faced the Khitan army on the battlefield stood in opposition, including General So Hui, commander of an army group north of Anju.

While the bureaucrats argued in Kaesong, General Xiao launched a sudden attack across the Ch'ongch'on River directly at the Koryo army headquarters in Anju. The Khitan assault was quickly repulsed, but it had the effect of agitating the royal court to a state of near panic. In an effort to calm the court nobility, General So Hui volunteered to negotiate directly with General Xiao. The one key factor influencing the negotiations, and both parties knew it, was the heavy pressure being exerted on the Liao state by Song China. In face to face talks with his Khitan counterpart, General So bluntly told General Xiao the Khitan had no basis for claims to former Parhae territory. In fact, since the Koryo dynasty was without question successor to the former Koguryo kingdom, that land rightfully belonged under Koryo's domain. In a cleverly veiled threat, So Hui reminded General Xiao that the Liaodong Peninsula was also territory once under the dominion of Koguryo. The Manchurian territories, including the Khitan capital at Liaoyang, should properly belong to Koryo.

After pushing General Xiao into a corner, So Hui gave the Khitan commander a "golden bridge over which he could escape" from his now difficult position. He told General Xiao that the activities of the Jurchen tribes south of the Yalu River hampered friendly relations between their two countries. Once the Jurchen were driven from the area, Koryo would extend its territory north to the Yalu River. The resulting land link between Koryo and the Liao state would, in time, make it much easier to establish friendly diplomatic relations. Faced with the alternative of withdrawing his armies from Koryo or fighting a major war on two fronts, General Xiao felt compelled to accept the logic of So Hui's arguments. In a final remarkable act, General So obtained Khitan consent to allow the region up to the Yalu River to be incorporated into Koryo territory. General Xiao and the Khitan army not only returned to Liao without having achieved their goals, but the invasion literally ended with the Khitan giving up territory along the southern Yalu River to King Songjong. So Hui's brilliant diplomatic maneuver underscored his correct understanding of both the contemporary international situation and Koryo's position in the region.

Following an exchange of prisoners, the Khitan army withdrew back across the Yalu River. The following year, Koryo and the state of Liao established formal diplomatic relations. In an effort to help the process along, Koryo temporarily suspended its diplomatic relations with Song China. King Songjong promptly took advantage of the situation and ordered his armies to drive the Jurchen tribes out of the northwest. Koryo moved into the area of the lower Yalu River and established a monopoly market for trade at the Liao city (modern Uiju) on the southern bank of the Yalu River.

King Songjong restructured the military forces of Koryo's central government into Six Divisions and the Two Guards. The Six Divisions included the Left and Right Division, the Divine Tiger Division, the Elite Striking Division, the Internal Security Division, the Thousand Bull Division, and the Capital Guards Division. The Two Guards units, the Soaring Falcon Guards and the Dragon-Tiger guards, were the kings personal bodyguards. A general commanded each of the Six Divisions and each of the Two Guards. These men also belonged to the Council of Generals, the military counterpart to the civilian Privy Council. An officer commanded each of the army's forty-five regiments and met regularly with other regimental commanders in the Council of Commanders. The one thousand man regiments included cavalry, infantry, prison guards, army ceremonial, navy ceremonial, and gate guards units.

King Songjong expected further Khitan incursions and ordered the construction of what became known as the Six Garrison Settlements to extend the power of Koryo all along the banks of the Yalu River. Peasant laborers built massive fortresses in the coastal plains and foothills between the Ch'ongch'on and Yalu Rivers near the modern cities of Uiju, Yongch'on, Sonch'on, Ch'olsan, Kusong, and Kwaksan. With its modernized defensive fortifications completed, Koryo reopened diplomatic relations with Song China. Khitan Emperor Shengzong viewed this defiant action and the growing strength of Koryo forces stationed south of the Yalu River with alarm. He not only voiced displeasure over these developments, but demanded that Koryo turn over its Six Garrison Settlements to the Liao empire. King Songjong immediately rejected his demand out of hand, thereby causing tensions between the Liao state and Koryo to heighten once again.

 http://koreanhistoryproject.org/Ket/C04/E0406.htm

In 1009, one of the dowager queen's sons maneuvered to force King Mokchong to abdicate in favor of the queen's grandson. The young king responded to this serious challenge to his own succession by appointing a close relative, the son of former King Kyongjong, as the Crown Prince. To secure his personal safety, Mokchong turned for help to one of his most powerful military commanders, General Kang Cho, the military administrator for the northwest district. He ordered General Kang to Kaesong from the Pyongyang Garrison and charged him with the protection of the crown. General Kang dutifully brought his troops into the capital and, in a brief period of terror at the royal palace, viciously eliminated the dowager queen and members of the Kim Ch'i-yang faction responsible for the attempted coup.

Like Wiman of Old Choson, Kang Cho had far stronger ambitions than Mokchong ever imagined. General Kang quickly turned against the young king, assassinated him, and appointed himself supreme military commander of the Koryo army. The young Crown Prince, with the approval of the powerful Kim Un-bu clan of Ansan, assumed the throne as King Hyonjong, only to discover he reigned over a government now under the control of General Kang Cho.

North of the Yalu River, Liao Emperor Shengzong closely monitored the political turmoil in Kaesong . Five years after his victory over the Song Chinese, the Liao emperor remained incensed over Koryo's trade monopoly with Song China and King Songjong's efforts to subjugate the Jurchen tribes in the northeast. Shengzong took particular offense at the brutal massacre of some ninety-five members of a Jurchen embassy whom he considered to be Liao subjects.

Kang Cho's bloody coup in Kaesong provided the Liao emperor an opportune pretext to invade Koryo under the guise of avenging King Mokchong's murder. In the winter of 1010, an army of 400,000 Khitan troops left the Naewon-song Fortress under the personal command of Emperor Shengzong and marched across the frozen Yalu River into the Koryo frontier. General Kang successfully fought off the first Khitan assault from defensive positions around the Sonch'on Garrison. Undaunted, the Khitan warriors regrouped and launched a second attack. This time they overran the garrison and captured General Kang. Despite repeated demands from the Khitan emperor that Kang Cho vow allegiance to him, the heroic Koryo general steadfastly refused to bow in submission. Emperor Shengzong executed him on the spot.

Emperor Shengzong's army defeated the Sonch'on Garrison and easily pierced Koryo's defenses, bypassing the coastal garrison at Kwaksan and pushing south to lay siege to the city of Pyongyang. Only a staunch defense by Koryo defenders prevented the fall of the city. When news of Kang Cho's death reached the royal court at Kaesong, the government nearly panicked. The king's ministers clamored for an immediate and unconditional surrender. King Hyongjong rejected the plea of his ministers and instead took the advice of one of his generals. Hoping to buy time for the remaining Koryo forces to reorganize and counterattack when the Khitan thrust lost its momentum, Hyongjong directed the court to move far south to the port city of Naju.

Emperor Shengzong continued his drive south. Khitan troops eventually reached the capital at Kaesong and took the city. The Khitan army savagely raped and pillaged its way through Kaesong, destroying a large number of precious monuments and documents. Hoping to end the hostilities, King Hyongjong attempted to sue for peace. The Koryo court quickly rounded up those officials responsible for the earlier massacre of the Jurchen envoys and handed them over to the Emperor Shengzong. The Khitan emperor haughtily ordered Koryo to cede the strategic border region then under the control of the Six Garrisons. He also demanded that if King Hyongjong wanted the Khitan to withdraw from Koryo, he should come to the capital at Liaoyang and show his obeisance to the Liao Dynasty. Hyongjong knew full well that such an act would amount to acknowledgement of Koryo's vassal status to the Liao emperor. The young king stubbornly refused such an absurd request and never took the royal journey north.

In the middle of critical negotiations with the Liao state in 1014, the military rebelled and led a coup d'état against the civil government. Two of the government's leading civil officials were beheaded. Ultimately however, the coup solved nothing. The underlying conditions that triggered the military revolt neither disappeared nor abated for over a century. Military officers still suffered the arrogant domination of a civilian government which continued to put civil bureaucrats in positions to which military men, in principle at least, should have been appointed.

Despite their success on the battlefield, the Liao invasion brought the Khitan no particular advantage. After driving deep into the heart of Koryo, Emperor Shengzong and his troops found themselves ever more dependent on thinly stretched supply lines that ran between the Naewon-song Fortress and Kaesong. Fearing he might be cut off and isolated deep within Koryo, Shengzong decided to withdraw his army. Koryo's warriors counterattacked the Khitan mercilessly during its northward retreat and inflicted horrendous casualties. Between twenty and thirty thousand Khitan soldiers reportedly died in their frantic attempt to recross the Yalu River into Liao.

Emperor Shengzong was hardly finished dealing with Koryo. Once the Khitan army shook off its disastrous defeat, it continued to launch numerous small-scale attacks in Koryo's northwest frontier, while the emperor continued to pressure King Hyongjong to accept his demands. The royal court in Kaesong continued steadfastly to refuse the Khitan emperor. Simultaneous with negotiations to settle disputes with Kaesong, Emperor Shengzong readied his forces for yet another major offensive, the final bloodbath in the long cycle of Khitan invasions.

Khitan combat troops under the command of General Xiao Baiya held two cities on the Koryo side of the Yalu River in anticipation of taking the region of the Six Garrison Settlements by force. Construction workers labored throughout the summer and autumn of 1018 to build a large, well-fortified bridge across the Yalu, completing the project in the dead of winter. General Xiao led a force of 100,000 men across the completed bridge onto Koryo's frozen countryside Koryo in December of that year. Columns of Koryo troops ambushed the Khitan from the moment they set foot on Koryo territory. After breaking out of the ambush, the Khitan army drove southward, only to meet even stiffer resistance in the region around the capital of Kaesong.

The Khitan were beset by continuous harassing attacks, forcing General Xiao to abandon all thoughts of conquest. His attention soon focused on the grave problem of trying to extricate himself from the hellish winter of northwest Korea. In their rush north toward the Yalu River, the Khitan army retreated headlong into the well defended Kusong Garrison near the northwestern town of Kuju. Koryo's General Kang Kam-ch'an led a massive attack that all but annihilated the Khitan army. Barely a few thousand of the Liao troops survived the bitter defeat at Kusong. Four years later, Koryo and the Liao dynasty reached a negotiated peace agreement and established normal relations. The Khitan never again invaded Koryo.

Koryo's defenses had weakened dramatically in the generation following General Kang Cho's death . Immediately following Koryo's peace agreement with the Liao dynasty, the royal court mobilized a labor force said to number upwards of 304,000 men to begin rebuilding the capital at Kaesong. In 1033, Koryo undertook a massive construction program to build a great defensive wall across its northern frontier to block not only the Khitan, but the Jurchen of eastern Manchuria as well. After eleven years of intensive labor, the massive rampart, modeled after China's northern defense line, linked fourteen walled towns in a line that stretched northward from the mouth of the Yalu River, through the mountains near the headwaters of the Ch'ongch'on and Taedong Rivers, to the east coast near Toryonp'o, the modern port of Yonp'o. 

http://koreanhistoryproject.org/Ket/C05/E0501.htm

In the Koryo dynasty, the northern tribes of Qidan, N zhen, Mongols were very strong, but by waging fierce struggles against them Koryo safeguarded the country and its people.
Koryo implemented a policy of expanding northward from the beginning of its national foundation. Qidan, which stood in confrontation with Song, felt uneasy with Koryo's pro-Song and northward expansion policies and frequently tried to invade Koryo. Under the reign of King Songjong, Koryo's So Hui had a bout with the invading Qidan commander, and retrieved six towns south of the Yalu River. During the reign of King Hyonjong, the Koryo army under the command of Kang Kam-ch'an nearly destroyed the Qidan army which invaded Koryo in Kwiju for the third time. This is known as the Victory of Kwiju (1019) In the 12th century, the N zhen tribe expanded their power to cover the northeastern frontier territory of Koryo. A special unit led by Yun Kwan conquered and built nine walls around the area because of the repeated appeals by the N zhen tribe when this territory was returned.
Afterwards, the N zhen, which had regained much strength, founded the nation of Jin and became a powerful nation dominating northern China. Koryo received pressure from Jin for a time, and to repel this, the monk Myoch'ong proposed relocating the capital to Sogyong and sending an expedition against Jin.

http://world.kbs.co.kr/vietnamese/korea/korea_history_con41.htm

 In 1009, after the Korean King was deposed, Shengzong invaded Korea with 400,000 men, and burned the Korean capital at Kaekyong.

http://en.wikipedia.org/wiki/Emperor_Shengzong_of_Liao

In AD 1018, General Kang Gam-chan defeated Khitans led by General So Bae-ap at the battle of Gui-ju, which forced them to give up their territorial ambition for Koryo.

www.chinahistoryforum.com/ index.php?showtopic=509&st=15

Khitans' great invasion in 1018 was annihilated by Kang Kamchan.

The long wall stretching from the mouth of the Yalu a thousand li eastward to the sea, laboriously built over a twelve year peirod from 1033 to 1044 was intended for defense not only against Khitan but also against the Jurchen.

http://eunmee.com/wiki/ReadingKoreaOldAndNew

926 : Balhae destroyed by Liao

Balhae:

refuges to Koryo

assimiliated to Liao with Jurchen

Liao initiated attacks in 983, in 985, in 989

Invasions :

>993 : So Hui (940-998)

 Koryo established contact with Sung in 985.  Koryo expanded northward and Liao eastward until they confronted one another at the Yalu river 989.  Koryo was invaded by Liao 993, and compelled to accept tributary vassal status and sever relations with Sung in 994.  (Henthorn 96-97; cf. Han 137-139, Lee 125)

http://jwsr.ucr.edu/archive/vol5/number3/wilkinson/

>1010

>1018

Koryo, having resumed trade and tribute to Sung, and then fallen into disorder, was invaded by Liao 1010 and 1018, made peace and resumed tribute to Liao in 1022.  (Henthorn 97-98; but cf. Han 139-142, Lee 126)

Koryo, now tributary to Liao, broke off tributary relations to Sung in 1030.  (Henthorn 97-98)

At some time in or near this period Koryo resumed tribute to Sung as well as Liao.  (v. Han 153)

Tungusic Jurchen from northeastern Korea and eastern Manchuria, settled Liao and Koryo vassals from the tenth century, steadily improved their organization, stopped tribute after 1100, defeated and made peace with Koryo, declared war on Liao 1114, and formed the state of Jin 1115.  Jin allied with Sung 1118, made Minyak a vassal 1124, and destroyed Khitan Liao 1125.  (Fairbank et al, 297; Lee 128; Han 153-154; Ebrey 150; Grousset 134-138; Chan, 52-59, 62)

        Koryo resisted Jin 1107 but then traded land for peace, and accepted vassal status in 1116 (Henthorn 110) or 1126 (Han 155-156; Lee 128; Chan 58).

Koryo's submission to Jin led to a suspension of cooperation with Southern Sung; but later Koryo sent tribute to both Sung and Jin, though its genuine overlord seems to have been Jin alone.  (Fairbank et al, 297; Lee 128; Han 155-156; Henthorn 110; Chan 58)

        A Mongol federation under Qabul Khan, at first a Jin vassal, had begun to raid Jin in the eastern Gobi (1135-1139), and defeated a Jin army.  Jin bought peace with lands, cattle and grain in 1147.  (Grousset 138, 197)

  Koryo continued as a Jin vassal, during years of intrigues and revolts.  (Henthorn 114; Lee 140-144; Han 158-163)

Koryo began this period as a Jin vassal plagued by internal rebellion.  (Han 163-164; Henthorn 116)  When the Mongol empire attacked Jin, Khitan declared independence and tried to refound Liao in southern Manchuria; when Mongols captured the Jin capital Yen-ching in 1215, they drove the Khitans into Koryo 1217, where Koryo combined with the Mongols to conquer them 1219.  The Mongols then enforced tribute on Koryo.  (Han 147-149; Henthorn 116-119; Lee 165-167; Grousset 259; but cf. Grousset 228 on the Later Liao)

In 993 a Khitan army of 900,000 crossed Koryo's northern border; but the Koreans were prepared, and their defense forced the Khitans to negotiate with So Hui, who persuaded them to withdraw. Summoned to squelch a subversive plot, military administrator Kang Cho eliminated the conspiracy of Kim Ch'i-yang but also assassinated King Mokchong, enthroning Hyonjong (r. 1009-31). However, this provided an opportunity for the Khitan Liao king to invade the next year with 400,000 troops. Kang Cho was captured and killed, and the Liao forces besieged P'yongyang. The capital at Kaesong was abandoned, resulting in raping, killing, and the destruction of many valuable monuments and documents. Yet Korean general Yang Kyu inflicted thousands of casualties on the retreating Liao army. Two military officers took control of the Koryo government in 1014. Four years later the Liao army crossed the frontier again; but a reorganized Koryo army decisively defeated them, and only a few Liao troops survived to return home the next year. In 1018 King Hyonjong tried to reform provincial governments by ordering their staffs to investigate the people's hardships, abilities of head clerks, crime, and the clerks' loss of public funds. Koryo used 30,000 laborers to build a wall around the capital in 1029, and between 1033 and 1044 they constructed a wall along the entire northern border that stretched from the mouth of the Yalu River on the west coast to Kwangpo on the east coast.

http://www.san.beck.org/3-10-Koreato1875.html#3

A large Khitan army invaded Koryo in 993. The Koreans fought them and their Liao empire invasion again in 1009 and then built walls around the capital and in the north

 When the Jurchen invaded Koryo in 1104, an army of 170,000 was organized that even included a unit of Buddhist monks; three years later the Jurchen forces were routed at Chongpyong.

In 1019, the Goryeo Army completely destroyed the 100,000 Khitan's army at Guiju.

http://english.metro.seoul.kr/today/about/about_03disc_0303.html

 http://www.hapkidoschule.de/his_korea.htm

The Manchurian territory of Balhae was now officially renamed Liao by the Khitans who initiated attacks in 983, in 985, in 989, and in 993, continuing to harass Goryeo. However, in 993, Koryo's commanding general So Hui (940-998), facing a stalemate with the Liao army, convened peace talks with Liao general Hsiao to end the enmity with the recognition of the Koryo's territorial rights of south of the Amnokkang river.

http://misspelled.guidecentral.com/korea.html

The Khitan rose to power and began to confederate, transforming their old tribal league into a centralized organization.  They conquered Parhae in 926 and , officially came to be caled Liao in 938.  As noted earlier, the people of Paehae fled to Koryo, but Liao was now ready to strike, and Koryo tried in vain to open diplomatic relations.  Liao initiated attacks in 983, in 985, in 989, and in 993, continuing to harass Koryo.  However, in 993, Koryo's commanding general So Hui (940-998), facing a stalemate with the Liao army, convened peace talks with Liao general Hsiao to end the enmity with the recognition of the Koryo's territorial rights of south of the Amnokkang river.

Diplomatic relations were opened between the two states in 994.  But Liao attached again in 1010 and the Koryo king fled to the south.  The conflict became more complicated as the northern Jurchen tribes grew stronger in the Korean border area of Manchuria

http://www.koreaneslcafe.com/KoreanLife/History/History_5.html

After the collapse of the Tujue and Uighur empires, the northern tribes broke up, and again began to fight. Some of the Uighurs who had been driven out of Mongolia by the Kirghiz escaped to the Turpan Basin where they established the Huigu state. Meanwhile, in 901, the Qidan rose to power again under the leadership of Yelu Abaoji. He established a new Qidan state and called it Liao. His forces marched east to conquer the Pohai state in 926, then moved north to break up the confederation of the Heishui Moge. Hence the Heishui Moge was split into two branches: the Shu Nyzhen in the south, and the Sheng Nuzhen in the north. The former was absorbed by the Liao and later accepted the Liao's overlordship.

http://www.paulnoll.com/China/Dynasty/dynasty-five-dynasties.html