The military history of Goguryeo involves wars with other Korean kingdoms,

Chinese dynasties Dynasties in Chinese history, or Chinese dynasties, were hereditary monarchical regimes that ruled over China during much of its history. From the legendary inauguration of dynastic rule by Yu the Great circa 2070 BC to the abdication of t ...

, nomadic states and tribes, and Wa Japan.

Goguryeo Goguryeo (37 BC–668 AD) ( ) also called Goryeo (), was a Korean kingdom located in the northern and central parts of the Korean Peninsula and the southern and central parts of Northeast China. At its peak of power, Goguryeo controlled most ...

was a highly militaristic state; it was a powerful empire and one of the great powers in

East Asia East Asia is the eastern region of Asia, which is defined in both geographical and ethno-cultural terms. The modern states of East Asia include China, Japan, Mongolia, North Korea, South Korea, and Taiwan. China, North Korea, South Korea and ...

, until it was defeated by a

Silla Silla or Shilla (57 BCE – 935 CE) ( , Old Korean: Syera, Old Japanese: Siraki2) was a Korean kingdom located on the southern and central parts of the Korean Peninsula. Silla, along with Baekje and Goguryeo, formed the Three Kingdoms of K ...

–

Tang Tang or TANG most often refers to: * Tang dynasty * Tang (drink mix) Tang or TANG may also refer to: Chinese states and dynasties * Jin (Chinese state) (11th century – 376 BC), a state during the Spring and Autumn period, called Tang (唐) b ...

alliance in 668 after prolonged exhaustion and internal strife caused by the death of

Yeon Gaesomun Yeon GaesomunSome Chinese and Korean sources stated that his surname was Yeongae () and personal name was Somun (), but the majority of sources suggest a one-syllable surname and a three-syllable personal name. (594–666) was a powerful militar ...

Conflicts with other Korean states

Baekje

and

Baekje Baekje or Paekche (, ) was a Korean kingdom located in southwestern Korea from 18 BC to 660 AD. It was one of the Three Kingdoms of Korea, together with Goguryeo and Silla. Baekje was founded by Onjo, the third son of Goguryeo's founder Jum ...

were two of the

Three Kingdoms of Korea Samhan or the Three Kingdoms of Korea () refers to the three kingdoms of Goguryeo (고구려, 高句麗), Baekje (백제, 百濟), and Silla (신라, 新羅). Goguryeo was later known as Goryeo (고려, 高麗), from which the modern name ''Kor ...

; both claimed descent from the ancient Korean kingdom of

Buyeo Buyeo or Puyŏ (Korean: 부여; Korean pronunciation: u.jʌ or 扶餘 ''Fúyú''), also rendered as Fuyu, was an ancient kingdom that was centered in northern Manchuria in modern-day northeast China. It is sometimes considered a Korean ki ...

Onjo Onjo (?–28, r. 18 BC – AD 28) was the founding monarch of Baekje (백제, 百濟), one of the Three Kingdoms of Korea. According to the ''Samguk Sagi'' (삼국사기, 三國史記), he founded the royal family of Baekje. Background There ...

, the founder of Baekje, was said to be the second son of

Jumong Chumo (Hangul: 추모, Hanja: 鄒牟), posthumously Chumo the Holy (Hangul: 추모성왕, Hanja: 鄒牟聖王), was the founding monarch of the kingdom of Goguryeo, and was worshipped as a god-king by the people of Goguryeo and Goryeo. ''Chumo ...

, the founder of Goguryeo. Despite the common ancestry, the relationship between Goguryeo and Baekje was often contentious. During the 4th century, Geunchogo expanded Baekje's territory to the north at the expense of Goguryeo. In 369, Gogukwon, the monarch of Goguryeo, attacked Baekje with 20,000 troops, but was defeated by Crown Prince Geungusu at the

Battle of Chiyang A battle is an occurrence of combat in warfare between opposing military units of any number or size. A war usually consists of multiple battles. In general, a battle is a military engagement that is well defined in duration, area, and force ...

. In 371, Geungusu led 30,000 troops and attacked the fortress of

Pyongyang Pyongyang (, , ) is the capital and largest city of North Korea, where it is known as the "Capital of the Revolution". Pyongyang is located on the Taedong River about upstream from its mouth on the Yellow Sea. According to the 2008 populatio ...

, slaying Gogukwon in battle. Baekje was a powerful maritime nation whose influence extended across the sea to

Liaoxi Liaoxi () was a former province in Northeast China, located in what is now part of Liaoning and Jilin provinces. It existed from 1949 to 1954, and its capital was Jinzhou Jinzhou (, ), formerly Chinchow, is a coastal prefecture-level city ...

and

Shandong Shandong ( , ; ; alternately romanized as Shantung) is a coastal province of the People's Republic of China and is part of the East China region. Shandong has played a major role in Chinese history since the beginning of Chinese civilizati ...

in China, taking advantage of the weakened state of

Former Qin The Former Qin, also called Fu Qin (苻秦), (351–394) was a dynastic state of the Sixteen Kingdoms in Chinese history ruled by the Di ethnicity. Founded by Fu Jian (posthumously Emperor Jingming) who originally served under the Later ...

, and to

Kyushu is the third-largest island of Japan's five main islands and the most southerly of the four largest islands ( i.e. excluding Okinawa). In the past, it has been known as , and . The historical regional name referred to Kyushu and its surroun ...

in the Japanese archipelago. Gogukyang, a son of Gogukwon, invaded Baekje in 386. In 392,

Gwanggaeto the Great Gwanggaeto the Great (374–413, r. 391–413) was the nineteenth monarch of Goguryeo. His full posthumous name means "Entombed in ''Gukgangsang'', Broad Expander of Domain, Peacemaker, Supreme King", sometimes abbreviated to ''Hotaewang'' ...

led an attack on Baekje with 40,000 troops, capturing 10 walled cities. In response,

Asin Asin Thottumkal (born 26 October 1985), known mononymously as Asin, is a former Indian actress who appeared predominantly in Tamil, Hindi and Telugu films. She is a trained Bharatanatyam dancer. She has received three Filmfare Awards. She beg ...

, the monarch of Baekje, launched a counterattack on Goguryeo in 393 but was defeated. Asin invaded Goguryeo once more in 394, but was defeated again. After suffering multiple defeats against Goguryeo, Baekje's political stability began to crumble. In 395, Baekje was defeated once more by Goguryeo and was pushed south to its capital of

Wiryeseong Wiryeseong was the name of two early capitals of Baekje, one of the Three Kingdoms of Korea. Both are believed to have been in the modern-day Seoul area. According to ''Samguk Sagi'' (the oldest surviving Korean history book, written in the 12th ...

on the Han River. In the following year, in 396, Gwanggaeto led an assault on Wiryeseong by land and sea, using the Han River, and triumphed over Baekje. Gwanggaeto captured the Baekje capital and the defeated Asin submitted to him, surrendering a prince and 10 government ministers. Henceforth, Baekje lost its dominance in the central Korean peninsula and declined. In 400,

requested aid from Goguryeo in repelling an allied invasion by

, Gaya, and Wa. Gwanggaeto dispatched 50,000 troops and annihilated the enemy coalition. In 433, Baekje and Silla formed an alliance (

Hangul The Korean alphabet, known as Hangul, . Hangul may also be written as following South Korea's standard Romanization. ( ) in South Korea and Chosŏn'gŭl in North Korea, is the modern official writing system for the Korean language. The let ...

: 나제동맹,

Hanja Hanja (Hangul: ; Hanja: , ), alternatively known as Hancha, are Chinese characters () used in the writing of Korean. Hanja was used as early as the Gojoseon period, the first ever Korean kingdom. (, ) refers to Sino-Korean vocabulary, wh ...

: 羅濟同盟) to balance the Goguryeo threat to the north. In 472, Gaero, the ruler of Baekje, requested a military alliance with

Northern Wei Wei (), known in historiography as the Northern Wei (), Tuoba Wei (), Yuan Wei () and Later Wei (), was founded by the Tuoba (Tabgach) clan of the Xianbei. The first of the Northern and Southern dynasties#Northern dynasties, Northern dynasties ...

against Goguryeo, but was unsuccessful. In 475,

Jangsu Jangsu County (''Jangsu-gun'') is a county in North Jeolla Province, South Korea. It is well known for Jangsu-Galbi. Climate Twin towns – sister cities Jangsu is twinned with: * Anyang, South Korea (1996) * Hapcheon, South Korea (1999) ...

, the son of Gwanggaeto, launched an invasion by land and sea against Baekje, and captured the capital of

and executed Gaero. Baekje had no choice but to move its capital to mountainous

Ungjin Ungjin, also known as Gomanaru (Hangul: 고마나루, literally "bear port") is a former city on the Korean Peninsula. It was located in modern-day Gongju, South Chungcheong province, South Korea. It was the capital of Baekje from AD 475 to 538 ...

(present-day

Gongju Gongju ([]; Gongju-si) is a city in South Chungcheong province, South Korea. History Gongju was formerly named Ungjin and was the capital of Baekje from AD 475 to 538. In this period, Baekje was under threat from Goguryeo. Goguryeo had overrun ...

), 80 miles to the south, which provided a natural protection for the devastated kingdom. In 479, Baekje and Silla reaffirmed their alliance through marriage, which was the primary reason why Goguryeo was unable to conquer the entire peninsula. In 551, a Baekje–Silla alliance attacked Goguryeo in order to capture the important Han River region from Goguryeo, planning to split it between them. In 553, Baekje gained the critical region after expending itself with a series of costly assaults on Goguryeo fortresses, but Silla troops, arriving on the pretense of offering assistance, attacked the exhausted Baekje troops and took possession of the entire Han River region, leading to a war between the two former allies in which the Baekje monarch was killed. Baekje attacked Silla in 612, 624, and 627. Goguryeo and Baekje formed an alliance (

: 여제동맹,

: 麗濟同盟) in 642 aimed toward territorial restoration against Silla.

King Uija Uija of Baekje (599?–660, r. 641–660) was the 31st and final ruler of Baekje, one of the Three Kingdoms of Korea. His reign ended when Baekje was conquered by an alliance of the rival Korean kingdom Silla and China's Tang dynasty. Backg ...

attacked Silla and captured around 40 strongpoints in 642, and 7 more fortresses in 645. In 655, the Goguryeo–Baekje alliance captured 30 fortresses from Silla.

Silla

In 245, Dongcheon ordered an attack on

, but the two kingdoms entered into friendly relations in 248. Nulji, the king of Silla, who had been a vassal of

, broke off relations with Goguryeo in 454. Jangsu invaded Silla in 468, expanding his domain into parts of Gangwon Province, and again in 489, capturing 7 walled cities and expanding his domain into parts of

North Gyeongsang Province North Gyeongsang Province ( ko, 경상북도, translit=Gyeongsangbuk-do, ) is a province in eastern South Korea. The province was formed in 1896 from the northern half of the former Gyeongsang province, and remained a province of Korea until the ...

. Silla emerged as a major player in the Korean Peninsula after its betrayal of Baekje and conquest of the Han River region from Goguryeo in 553, but Goguryeo and Baekje applied political, military, and economic pressure against Silla. In 643, under attack by the Goguryeo–Baekje alliance, the Silla court dispatched

Kim Chunchu King Taejong Muyeol (604–661), born Gim Chunchu, was the 29th ruler of Silla, one of the Three Kingdoms of Korea. He is credited for leading the unification of Korea's Three Kingdoms. Background King Taejong Muyeol was born with the "sacred ...

to the

Tang dynasty The Tang dynasty (, ; zh, t= ), or Tang Empire, was an Dynasties in Chinese history, imperial dynasty of China that ruled from 618 to 907 AD, with an Zhou dynasty (690–705), interregnum between 690 and 705. It was preceded by the Sui dyn ...

to request military assistance, leading to Emperor Taizong's campaign against Goguryeo. In 660, Goguryeo's ally, Baekje, fell to the Silla–Tang alliance; the victorious allies continued their assault on Goguryeo for the next eight years but could not defeat

. However, Yeon Gaesomun died of a natural cause and civil war ensued among his three sons, leading the Silla–Tang alliance to launch a fresh invasion. In November 668, King Bojang surrendered to the Silla–Tang alliance and Goguryeo finally fell.

Conflicts with Chinese states

Han dynasty

became a significant independent kingdom in the first century, and began expanding its power in the region. Taejodae conquered neighboring

Okjeo Okjeo () was an ancient Korean tribal state which arose in the northern Korean peninsula from perhaps the 2nd century BCE to the 5th century CE. Dong-okjeo (Eastern Okjeo) occupied roughly the area of the Hamgyŏng provinces of North Korea, and ...

and

Dongye Dongye may refer to: *Eastern Ye, chiefdom in northeastern Korean peninsula from roughly 3rd-century BC to around early 5th-century AD Towns in China * Dongye, Wutai County, Shanxi *Dongye, Yangcheng County Dongye () is a town in Yangcheng Count ...

, and made repeated attacks against the Chinese commanderies and incursions into Liaodong, which would be continued by his successors.

Cao Wei

In 244,

Guanqiu Jian Guanqiu Jian (died 16 March 255), courtesy name Zhonggong, was a Chinese military general and politician of the state of Cao Wei during the Three Kingdoms period of China. Life Guanqiu Jian was from Wenxi County (), Hedong Commandery, which i ...

, a general of Han's successor state

Cao Wei Wei ( Hanzi: 魏; pinyin: ''Wèi'' <

Middle Chinese

: *''ŋjwei^C'' <

, defeated Dongcheon and briefly occupied and sacked Goguryeo's capital. Wei invaded again in 259 but was defeated at Yangmaenggok; according to the

Samguk Sagi ''Samguk Sagi'' (, ''History of the Three Kingdoms'') is a historical record of the Three Kingdoms of Korea: Goguryeo, Baekje and Silla. The ''Samguk Sagi'' is written in Classical Chinese, the written language of the literati of ancient Korea, ...

, Jungcheon assembled 5,000 elite cavalry and defeated the invading Wei troops, beheading 8,000 enemies.

Lelang commandery

As Goguryeo extended its reach into the

Liaodong Peninsula The Liaodong Peninsula (also Liaotung Peninsula, ) is a peninsula in southern Liaoning province in Northeast China, and makes up the southwestern coastal half of the Liaodong region. It is located between the mouths of the Daliao River (the ...

, the last Chinese commandery at

Lelang The Lelang Commandery was a commandery of the Han dynasty established after it had conquered Wiman Joseon in 108 BC and lasted until Goguryeo conquered it in 313. The Lelang Commandery extended the rule of the Four Commanderies of Han as far so ...

was conquered and annexed by Micheon in 313, bringing the remaining northern part of the Korean peninsula into the fold. This conquest resulted in the end of Chinese rule over territory in the northern Korean peninsula, which had spanned 400 years.

Former Yan

During the winter of 342, the

Xianbei The Xianbei (; ) were a Proto-Mongolic ancient nomadic people that once resided in the eastern Eurasian steppes in what is today Mongolia, Inner Mongolia, and Northeastern China. They originated from the Donghu people who splintered into the ...

Former Yan The Former Yan (; 337–370) was a dynastic state ruled by the Xianbei during the era of Sixteen Kingdoms in China. Initially, Murong Huang and his son Murong Jun claimed the Jin dynasty-created title "Prince of Yan," but subsequently, in 352, ...

, ruled by the

Murong Murong (; LHC: *''mɑC-joŋ''; EMC: *''mɔh-juawŋ'') or Muren refers to an ethnic Xianbei tribe who are attested from the time of Tanshihuai (reigned 156–181). Different strands of evidence exist linking the Murong to the MongolsТаск� ...

clan, attacked and destroyed Goguryeo's capital, Hwando, capturing 50,000 Goguryeo men and women to use as slave labor in addition to taking the queen mother and queen prisoner and exhuming the body of Micheon, and forced Gogukwon to flee for a while. The Xianbei also devastated

in 346, accelerating Buyeo migration to the Korean peninsula.

Later Yan

In 385, Gogukyang, the son of Gogukwon, invaded and defeated

Later Yan Yan, known in historiography as the Later Yan (; 384 – 407 or 409) was a dynastic state of China ruled by the Xianbei people, located in modern-day northeast China, during the era of Sixteen Kingdoms. All rulers of the Later Yan declared them ...

, the successor state of Former Yan. In 400, the

state of Later Yan, founded by the

clan in present-day

Liaoning Liaoning () is a coastal province in Northeast China that is the smallest, southernmost, and most populous province in the region. With its capital at Shenyang, it is located on the northern shore of the Yellow Sea, and is the northernmost ...

, attacked Goguryeo.

repulsed the enemy troops. In 402, Gwanggaeto retaliated and conquered the prominent fortress called 宿軍城 near the capital of Later Yan. In 405 and again in 406, Later Yan troops attacked Goguryeo fortresses in Liaodong (遼東城 in 405, and 木底城 in 406), but was defeated both times. Gwanggaeto conquered all of Liaodong. By conquering Liaodong, Gwanggaeto recovered the ancient domain of

Gojoseon Gojoseon () also called Joseon (), was the first kingdom on the Korean Peninsula. According to Korean mythology, the kingdom was established by the legendary founder named Dangun. Gojoseon possessed the most advanced culture in the Korean Pen ...

; Goguryeo controlled Liaodong until the mid-late 7th century.

Sui dynasty

In 589, the

Northern and Southern dynasties The Northern and Southern dynasties () was a period of political division in the history of China that lasted from 420 to 589, following the tumultuous era of the Sixteen Kingdoms and the Eastern Jin dynasty. It is sometimes considered as ...

period ended and the

Sui dynasty The Sui dynasty (, ) was a short-lived imperial dynasty of China that lasted from 581 to 618. The Sui unified the Northern and Southern dynasties, thus ending the long period of division following the fall of the Western Jin dynasty, and layi ...

unified China after four centuries of fragmentation. The Sui Empire reconquered

Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...

and defeated

Champa Champa (Cham: ꨌꩌꨛꨩ; km, ចាម្ប៉ា; vi, Chiêm Thành or ) were a collection of independent Cham polities that extended across the coast of what is contemporary central and southern Vietnam from approximately the 2nd cen ...

, sacking its capital, and conquered important lands in northern China and

Central Asia Central Asia, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes t ...

against Turks, Tibetans and proto-Mongolians. In 598,

made a preemptive attack on

, leading Emperor Wen to launch a counterattack by land and sea that ended in disaster for Sui. In 612, Emperor Yang mobilized a huge force said to number over a million men and invaded Goguryeo. Unable to overcome the defenses of Yodong (Liaodong) Fortress, Emperor Yang ordered 305,000 troops to attack the Goguryeo capital of

. However, General

Eulji Mundeok Eulji Mundeok (을지문덕) (Ulchi Mundok) was a military leader of early 7th century Goguryeo, one of the Three Kingdoms of Korea, who successfully defended Goguryeo against Sui China. He is often numbered among the greatest heroes in the m ...

baited the Sui troops and annihilated them at the

Battle of Salsu The Battle of Salsu was a major battle that occurred in the year 612 during the second campaign of the Goguryeo–Sui War between Goguryeo of Korea and Sui of China. Goguryeo won an overwhelming victory over the numerically superior Sui forces ...

; according to Chinese historical records: of the 305,000 Sui troops, a mere 2,700 returned. Emperor Yang lifted his siege of the

Korean fortress Korean fortresses are fortifications constructed by Koreans since the Three Kingdoms of Korea period. Koreans developed a unique and distinct fortress tradition. Korea, beginning with Goguryeo, has been called "a country of fortresses"; almost 2, ...

and withdrew his forces back to China. Emperor Yang was obsessed with defeating Goguryeo. He attacked Goguryeo again in 613 and 614, but failed against Goguryeo's defensive strategies, fierce resistance, and able leadership; furthermore, his campaign in 613 was cut short by internal discontent and floods back home. Emperor Yang's disastrous defeats in Korea greatly contributed to the collapse of the Sui dynasty.

Tang dynasty

Korean ambassadors during a audience with king Varkhuman of Samarkand

Emperor Taizong ascended the

throne in 626, and led many successful military campaigns. In 630, Emperor Taizong defeated the Eastern Turkic Khaganate, an ally of Goguryeo, bringing much of

under Tang control; he then conquered the

Tarim Basin The Tarim Basin is an endorheic basin in Northwest China occupying an area of about and one of the largest basins in Northwest China.Chen, Yaning, et al. "Regional climate change and its effects on river runoff in the Tarim Basin, China." Hydr ...

, and defeated the

Tibetan Empire The Tibetan Empire (, ; ) was an empire centered on the Tibetan Plateau, formed as a result of imperial expansion under the Yarlung dynasty heralded by its 33rd king, Songtsen Gampo, in the 7th century. The empire further expanded under the 38 ...

in 640. In 643,

Queen Seondeok Queen Seondeok of Silla ( ko, 선덕여왕 ; 595~610 – 17 February 647/January 8, Lunar Calendar) reigned as Queen Regnant of Silla, one of the Three Kingdoms of Korea, from 632 to 647. She was Silla's twenty-seventh ruler, and its first re ...

requested military aid against the Goguryeo–Baekje alliance. Tang forged an alliance with Silla, and began preparations for a major campaign against Goguryeo in 644. In 645, Emperor Taizong personally led a campaign against Goguryeo by land and sea with 113,000 Tang troops plus an unspecified number of tribal auxiliaries. His noted army captured a number of Goguryeo border fortresses, including the potent Yodong (Liaodong) Fortress, which had repulsed Emperor Yang in 612 and 613. Arriving outside Ansi Fortress on July 18, Emperor Taizong prepared to meet an approaching relief army, said to number 150,000 men, in battle. Emperor Taizong ordered

Li Shiji Li Shiji (594?The ''Old Book of Tang'' indicated that Li Shiji was 75 at the time of his death, while the ''New Book of Tang'' indicated that Li Shiji was 85 at the time of his death. Compare ''Old Book of Tang'', vol. 67 with ''New Book of Tang ...

to bait the Koreans with 15,000 troops, while

Zhangsun Wuji Zhangsun Wuji (; died 659), courtesy name Fuji (輔機), formally the Duke of Zhao, was a Chinese politician who served as a chancellor in the early Tang dynasty. He was Empress Zhangsun's brother, which made him a brother-in-law of Emperor Tai ...

's concealed troops would ambush them from behind. On the following day, the two sides clashed and Emperor Taizong inflicted a crushing defeat on the confused Koreans, inflicting 20,000 casualties and capturing 36,800 prisoners. Emperor Taizong then laid siege to Ansi Fortress; his troops attacked the

as many as six or seven times per day, but were repelled each time by the defenders. Unable to breach the adamant fortress despite months of siege, Tang eventually staked everything on the construction of a huge mound, designed to tower over the walls of the fortress; however, the defenders captured and successfully held the mound despite three days of frantic assaults by Tang troops. Furthermore, exacerbated by worsened conditions for the Tang army due to cold weather (and winter approaching) and diminishing provisions, Emperor Taizong was compelled to order a withdrawal from Goguryeo on October 13, but left behind an extravagant gift for

Yang Manchun Yang Manchun is the name given to the Goguryeo commander of Ansi Fortress in the 640s. Ansi Fortress was located on the Goguryeo–Tang border, probably present-day Haicheng. Yang is sometimes credited with saving the kingdom by his successful ...

, the commander of Ansi Fortress. Emperor Taizong attacked Goguryeo again in 647 and 648, but was unsuccessful. Defeating Goguryeo had been an obsession with Emperor Taizong, and after his death in 649, his son Emperor Gaozong continued his ambition. Upon the suggestion of

, the Silla–Tang alliance first conquered

in 660 to break up the Goguryeo–Baekje alliance, and then turned its full attention to Goguryeo. However, Emperor Gaozong, too, was unable to defeat Goguryeo led by

; one of Yeon Gaesomun's most notable victories came in 662 at the ''Battle of Sasu'' (蛇水), where he annihilated the Tang forces and killed the invading general

Pang Xiaotai Pang may refer to: Places *Siem Pang District, Cambodia *Pangnirtung or Pang, an Inuit hamlet on Baffin Island, Canada *Fo Pang (Chinese: 火棚), an area of Kowloon, Hong Kong *Pang, a hamlet in Leh district, Jammu and Kashmir, India *Pang, Mal ...

(龐孝泰) and all 13 of his sons. Hence, while Yeon Gaesomun was alive, Tang could not defeat Goguryeo.

Fall and aftermath

In 666 (though dates vary from 664–666), Yeon Gaesomun died of a natural cause and a civil war ensued among his three sons. His eldest son and immediate successor,

Yeon Namsaeng Yeon Namsaeng (연남생, 淵男生) (634–679) was the eldest son of the Goguryeo '' Dae Magniji'' (대막리지, 大莫離支; highest ranking official or dictator; "prime minister") Yeon Gaesomun (603?-665). In 665, Yeon Namsaeng succeeded hi ...

, defected to

and provided the secrets and weaknesses of Goguryeo to Emperor Gaozong, and played a critical role in the next invasion and downfall of Goguryeo. Yeon Gaesomun's second son,

Yeon Namgeon Yeon Namgeon (淵男建, 연남건) (635 ~ ? 연개소문의 맏아들인 연남생이 634년에 탄생했고 막내아들인 연남산이 639년 출생했으므로 적어도 1년 이상 차이가 난다.) was the second son of the Goguryeo mil ...

, resisted in the face of death, as opposed to his brother's treachery, and fought until the very end. Meanwhile, Yeon Gaesomun's younger brother, Yeon Jeongto, defected to the Silla side. The Tang–Silla alliance mounted a fresh invasion of Goguryeo in 667, aided by the defector Yeon Namsaeng, and in 668, finally vanquished the divided kingdom, which had been plagued by violent dissension, numerous defections, and widespread demoralization following the death of Yeon Gaesomun.

thus unified most of the Korean peninsula in 668, but the kingdom's reliance on Tang China had its price. Tang China attempted to impose its rule over the entire Korean peninsula, but Silla, aided by Goguryeo and Baekje refugees, forcibly resisted and expelled Tang. However, Silla's unification of the

was short-lived because the former Goguryeo general

Dae Joyeong Dae Joyeong (died 719) (; or in Korean) or Da Zuorong (大祚榮, 大祚荣, in Chinese), also known as King Go (; in Korean; Gao in Chinese), established the state of Balhae, reigning from 699 to 719. Life Early life Dae Joyeong wa ...

led remnants of Goguryeo, united with the Mohe people, and established

Balhae Balhae ( ko, 발해, zh, c=渤海, p=Bóhǎi, russian: Бохай, translit=Bokhay, ), also rendered as Bohai, was a multi-ethnic kingdom whose land extends to what is today Northeast China, the Korean Peninsula and the Russian Far East. It wa ...

, a successor of Goguryeo. Balhae eventually reconquered and retained much of Goguryeo's former territory. The

general

Gao Juren Gao , or Gawgaw/Kawkaw, is a city in Mali and the capital of the Gao Region. The city is located on the River Niger, east-southeast of Timbuktu on the left bank at the junction with the Tilemsi valley. For much of its history Gao was an impor ...

ordered a mass slaughter of Sogdian Caucasians from West and Central Asia, identifying them through their big noses and lances were used to impale Caucasian children when he stormed Beijing (

Jicheng (Beijing) Ji or Jicheng was an ancient city in northern China, which has become the longest continuously inhabited section of modern Beijing. Historical mention of Ji dates to the founding of the Zhou dynasty in about 1045BC. Archaeological finds in sout ...

) from

An Lushan An Lushan (; 20th day of the 1st month 19 February 703 – 29 January 757) was a general in the Tang dynasty and is primarily known for instigating the An Lushan Rebellion. An Lushan was of Sogdian and Göktürk origin,Yang, Zhijiu, "An Lushan ...

when he defeated An Lushan's rebels. Balhae became a powerful empire like its predecessor, but its eventual end came at the hands of the

Khitan Empire The Liao dynasty (; Khitan: ''Mos Jælud''; ), also known as the Khitan Empire (Khitan: ''Mos diau-d kitai huldʒi gur''), officially the Great Liao (), was an imperial dynasty of China that existed between 916 and 1125, ruled by the Yelü ...

in 926. Balhae's end was a decisive event in Northeast Asian history for it was the last Korean kingdom to hold territory in

Manchuria Manchuria is an exonym (derived from the endo demonym " Manchu") for a historical and geographic region in Northeast Asia encompassing the entirety of present-day Northeast China (Inner Manchuria) and parts of the Russian Far East (Outer Manc ...

. Goguryeo was revived once more in 918 by successor state

Goryeo Goryeo (; ) was a Korean kingdom founded in 918, during a time of national division called the Later Three Kingdoms period, that unified and ruled the Korean Peninsula until 1392. Goryeo achieved what has been called a "true national unificati ...

, founded by

Wang Geon Taejo of Goryeo (31 January 877 – 4 July 943), also known as Taejo Wang Geon (; ), was the founder of the Goryeo dynasty, which ruled Korea from the 10th to the 14th century. Taejo ruled from 918 to 943, achieving unification of the Later Thre ...

, a descendant of Goguryeo nobility. In 937, much of the ruling class and the last crown prince of collapsed

fled to Goryeo, where he was warmly welcomed and included into the ruling family by Wang Geon, thus unifying the two successor nations of

Conflicts with nomadic states

In 395,

invaded the Khitan Baili clan to the west on the

Liao River The Liao River () is the principal river in southern Northeast China, and one of the seven main river systems in China. Its name derived from the Liao region, a historical name for southern Manchuria, from which the Liaoning province, Liaodong P ...

, destroying 3 tribes and 600 to 700 camps. In 398, Gwanggaeto conquered the

Sushen Sushen is the modern Chinese name for an ancient ethnic group of people who lived in the northeastern part of China (in the area of modern Jilin and Heilongjiang) and what is in modern times the Russian Maritime Province and some other Siberi ...

people to the northeast, who were Tungusic ancestors of the

Jurchens Jurchen (Manchu language, Manchu: ''Jušen'', ; zh, 女真, ''Nǚzhēn'', ) is a term used to collectively describe a number of East Asian people, East Asian Tungusic languages, Tungusic-speaking peoples, descended from the Donghu people. They ...

and

Manchus The Manchus (; ) are a Tungusic East Asian ethnic group native to Manchuria in Northeast Asia. They are an officially recognized ethnic minority in China and the people from whom Manchuria derives its name. The Later Jin (1616–1636) and Q ...

. In 479,

invaded the Khitans, and then attacked the

Didouyu The Didouyu (地豆于) or Didougan (地豆干) was a tribe during the 5th-century in west Manchuria. Their territory included the Tujue (Eastern Turk, on their west), the Rouran, and the Khitan (on their southeast). They were attacked by both G ...

with his

Rouran The Rouran Khaganate, also Juan-Juan Khaganate (), was a tribal confederation and later state founded by a people of Proto-Mongolic Donghu origin.*Pulleyblank, Edwin G. (2000)"Ji 姬 and Jiang 姜: The Role of Exogamic Clans in the Organizati ...

allies.

Conflicts with Japanese states

In 404, Gwanggaeto defeated an attack by the Wa from the

Japanese archipelago The Japanese archipelago (Japanese: 日本列島, ''Nihon rettō'') is a archipelago, group of 6,852 islands that form the country of Japan, as well as the Russian island of Sakhalin. It extends over from the Sea of Okhotsk in the northeast to t ...

on the southern border of what was once the

Daifang commandery The Daifang Commandery was an administrative division established by the Chinese Han dynasty on the Korea, Korean Peninsula between 204 and 314. History Gongsun Kang, a warlord in Liaodong, separated the southern half from the Lelang commandery ...

, inflicting enormous casualties on the enemy.