Yeon Gaesomun


 * For the historical drama, see Yeon Gaesomun (TV series).

Yeon Gaesomun (603–666) was a powerful and controversial military dictator and Generalissimo in the waning days of Goguryeo, which was one of the Three Kingdoms of ancient Korea. Yeon is also remembered for a number of successful resistance in military conflicts with Tang Dynasty under Emperor Li Shimin and his son Emperor Gaozong. Their failure to Yeon was the only defeat that Emperor Li Shimin ever suffered on the battlefield.

Traditional Korean histories paint Yeon Gaesomun as a despotic leader, whose cruel policies and disobedience to his monarch led to the fall of Goguryeo. However, his achievements in defending Goguryeo against Chinese onslaughts have inspired Korean nationalist historians, most notably the 19th century Korean historian and intellectual Shin Chaeho, to term Yeon Gaesomun the greatest hero in Korean history. Many Korean scholars today echo Shin and praise Yeon Gaesomun as a soldier-statesman without equal in Korean history, though other scholars strongly disagree. Chinese and Japanese scholars continue to hold an unfavorable view of Yeon Gaesomun.

Biography
Yeon Gaesomun was the first, and oldest son of Yeon Taejo, the Prime minister (막리지, 莫離支) of Goguryeo during the reigns of King Pyeongwon of Goguryeo and King Yeongyang of Goguryeo. It is known that the Yeon family was always of high rank and status in Goguryeo. Yeon's grandfather Yeon Ja-yu was also a prime minister of Goguryeo. Information about Yeon Gaesomun comes largely from the Samguk Sagi's accounts of King Yeongnyu and King Bojang (Goguryeo vols. 8-10) and its biography of Yeon Gaesomun (vol. 49), surviving tomb engravings belonging to his sons Yeon Namsaeng and Yeon Namsan, and the biographies of those same sons that appear in the New Book of Tang.

Tang Chinese historical records give Yeon Gaesomun's surname as Cheon (泉, Quan in Chinese, meaning "spring"), because Yeon (淵, Yuan in Chinese, meaning "riverhead") was the given name of Emperor Gaozu of Tang (Li Yuan, 李淵), founder and first emperor of Tang, and thus taboo to apply to another by Chinese tradition (see naming taboo). He is also sometimes referred to as Gaegeum (개금/蓋金). In Nihon Shoki, he appears as Iri Kasumi (伊梨柯須彌).

Very little is known of Yeon's early days, until he became the Governor of the Western province (西部大人), where he oversaw the building of the Cheolli Jangseong, a network of military garrisons to defend the Liaodong area from Tang invaders.

Overthrow of the throne
In the winter 642, King Yeongnyu was apprehensive about his general Yeon Gaesomun and was plotting with his other officials to kill Yeon. When Yeon received the news, Yeon Gaesomun arranged a lavish banquet to celebrate his rise to the position of Eastern Governor to which one hundred of the opposing politicians of the kingdom were invited. Yeon's soldiers ambushed and killed all one hundred ministers present. Yeon Gaesomun then proceeded to the palace and murdered the king. According to traditional Chinese and Korean sources, Yeon's men dismembered the dead king's corpse and discarded it without proper ceremony.

After placing King Bojang (r. 642-668),a nephew of King Yeongnyu, on the Goguryeo throne, Yeon appointed himself Dae Mangniji (대막리지, 大莫離支, Generalissimo). Subsequently, in this role Yeon went on to assume de facto control over Goguryeo affairs of state until his death around 666.

His role in the murder of the Goguryeo king was taken as the primary pretext for the failed Tang invasion of 645.

642 coup d'etat by Yeon Gaesomun came as the culmination of a lengthy power struggle between the military and the executive officials; between those who favored appeasement towards the Tang Dynasty and those who advocated military confrontation; and Yeon belonged to the hard-liners. Traditional Chinese and Korean historians believed that his motive was simply his thirst for power. With the rise of Korean nationalism, many revisionist Korean historians now assert that his motive was to make Goguryeo assume a tougher stance against Tang China. At the time the emperor was basically submitting to Tang for a peaceful diplomatic relationship.

Wars with China
The series of wars between Goguryeo and Tang comprise some of the most important events in the ancient history of Northeast Asian, for many maintain they were the main cause of the Silla-Tang alliance, the ultimate demise of once-powerful Goguryeo, and the unification of the peninsula under Silla rule. Yeon was a central protagonist in this series of conflicts, as well as its chief cause.

At the outset of his rule, Yeon took a briefly conciliatory stance toward Tang Dynasty China. For instance, he supported Taoism at the expense of Buddhism, and to this effect in 643 sent emissaries to the Tang court requesting Taoist sages, eight of whom were brought to Goguryeo. This gesture is considered by some historians as an effort to pacify the Tang and buy time to prepare for the Tang invasion Yeon thought inevitable given his ambitions to annex Silla.

Relations with Tang deteriorated when Goguryeo launched new invasions of Silla. In 645 the Goguryeo-Tang Wars began and Taizong's noted military acumen enabled him to conquer a number of major Goguryeo border fortresses.

Eventually, however, Taizong's invasion was met with two major setbacks. First, Taizong's main army was stymied and bogged down for several months at Ansi Fortress due to the resistance of the celebrated commander, Yang Man-chun. Second, the elite marine force that Taizong sent to take Pyongyang, Goguryeo's capital, was defeated by Yeon who, according to the Joseon Sanggosa, then immediately marched his legions to relieve Yang's forces at Ansi Fortress.

Taizong, caught between Yang's army in the front and Yeon's counter-attacking forces closing in from behind, as well as suffering from the harsh winter and dangerously low food supplies, was forced to retreat homeward (Zizhi Tongjian). During the retreat itself, a large number of Taizong's soldiers were killed by Yeon Gaesomun and his pursuing army. However, Taizong and the invading army survived. Taizong's first invasion of Goguryeo was thus defeated. However, Taizong succeeded in inflicting heavy casualties on Goguryeo.

It is speculated that after Taizong's failure to conquer Goguryeo his personal rivalry with Yeon Gaesomun became an obsession with both him and his son Gaozong. They invaded Goguryeo two more times in 661 and were unsuccessful in both attempts—perhaps most notably during Yeon's victory over the Tang forces in 662. Chinese general Pang Xiaotai (龐孝泰) was defeated by Goguryeo forces at Sasu River (蛇水, probably Botong River) and was killed along with his 13 sons, Su ran into harsh snowstorms and withdrew. With increasing domestic turmoil in China, Tang was once again forced to retreat.

However, the population and economy were severely damaged after the three major invasions and never fully recovered. Silla and Tang continued their mutual struggle for over 8 years. In 668, two years after Yeon's death, Goguryeo finally met its demise. However, at least during the rule of Yeon Gaesomun the Tang-Silla alliance was unable to subdue Goguryeo.

Death
The most likely date of Yeon's death is that recorded on the tomb stele of Namsaeng, Yeon Gaesomun's eldest son: the twenty-fourth year of the reign of Bojang (665). However, the Samguk Sagi records the year as 666, and the Japanese history Nihonshoki gives the year as the twenty-third year of the reign of King Bojang (664).

Yeon Gaesomun had at least three sons, (eldest to youngest) Yeon Namsaeng, Yeon Namgeon, and Yeon Namsan. After his death, the country was weakened by a succession struggle between his brother and three sons, and in 668 fell relatively swiftly to the Silla-Tang armies.

Controversy and Legacy
Yeon has been one of the most controversial figures in Korean history. The many controversies surrounding him revolve around two issues: his character and his role in the fall of Goguryeo.

Later Confucian scholars have mercilessly criticized Yeon for the coup and the regicide that brought him to power. In their eyes, he was a disloyal subject who sought personal power above all else. In particular, extant Tang and Silla sources have consistently portrayed Yeon as a brutal and arrogant dictator. According to their testimony, for instance, Yeon carried five swords at a time, and would have men prostrate themselves so that he might use their backs to mount or dismount his horse. Yeon's modern-time defenders, however, dismiss these Tang and Silla sources as biased calumnies of enemy historians. Moreover, they argue that Yeon's subsequent single-mindedness and success in defending Goguryeo testifies his genuine patriotism (though Taizong's first invasion was provoked by Yeon's attacks on Silla, and subsequent attacks were possibly due to Taizong and his son's personal hatred against Yeon).

In terms of his role in the downfall of Gogureyo, Yeon's detractors blame Yeon for needlessly provoking the Tang to attack Goguryeo (see above) and thereby ensuring its downfall. They point out that, while Goguryeo remained a formidable regional power before Yeon assumed power, it was completely destroyed by Silla and Tang within a short time soon after his death. They also point out that the population of Gogureyo decreased dramatically during Yeon's rule, and much of the economy was destroyed due to constant wars with Tang China and Silla. Yeon's defenders rejoin by claiming that the Tang would have invaded Goguryeo, regardless of Goguryeo's attitude vis-a-vis Tang (although a major reason for Taizong's first invasion of Goguryeo was Yeon's invasion of Silla, another Korean kingdom that allied with Tang).

Another controversy that arises is the sources actually used to support the defeat of the Tang Dynasty. Some sources such as Shin's Joseon Sanggosa claim that Taizong was forced into the outskirts of Beijing. However, Shin's account has been challenged on the basis that it lacked support in traditional Korean and Chinese sources. The ancient Korean history Samguk Sagi and ancient Chinese histories Book of Tang, New Book of Tang, and Zizhi Tongjian put the figure at 20,000, stating that there were only 100,000 Tang soldiers used total. The modern Chinese historian Bo Yang has speculated that the Yeon had the records altered so that he could claim credit for Yang Manchun's victory over Tang.

In popular culture

 * Portrayed by Jo Kyung-hwan in 1992 television series The Three Kingdoms.
 * Portrayed by Lee Won-jong in 2003 film Once Upon a Time in a Battlefield and its 2011 sequel Battlefield Heroes.
 * Portrayed by Yoo Dong-geun and Lee Tae-gon in 2006-2007 television series Yeon Gaesomun.
 * Portrayed by Kim Jin-tae in 2006-2007 television series Dae Jo Yeong.
 * Portrayed by Choi Dong-joon in 2012-2013 television series The King's Dream.
 * Portrayed by Choi Min-soo in 2013 television series The Blade and Petal.