[Lee Sang-hoon's Korean History] Is the Battle of Gibeolpo, Which Marked the End of the Three Kingdoms Unification, a Myth?

A New Perspective on the End Point of the Nara-Tang War

The Silla-Tang allied forces destroyed Baekje in 660 and even Goguryeo in 668. However, not long after, Silla and Tang clashed over dominance of the Korean Peninsula. This was the Silla-Tang War. The war, which intensified from 670, went through the Battle of Maesoseong in 675 and ended with the Battle of Gibeolpo in 676. The Silla victory at the Battle of Gibeolpo in November 676 marked the end of the Silla-Tang War. Therefore, the point of the Three Kingdoms' unification is November 676.

There is little disagreement in the domestic academic community that the end of the Silla-Tang War is marked by the Battle of Gibeolpo. However, Japanese and Chinese scholars view the Battle of Gibeolpo very differently. Japanese historian Ikeuchi Hiroshi (池內宏, 1879?1952) argued that the compiler of the Samguk Sagi made an error by recording an event that occurred in 671 under the year 676. He cited records from the Old Book of Tang (舊唐書) and the New Book of Tang (新唐書) as evidence.

The Tang general who commanded the forces at the Battle of Gibeolpo was Xue Rengui (설인귀, 薛仁貴). Ikeuchi claimed that during the Shangyuan era (上元年間), Xue Rengui was in exile and thus could not have participated in the battle. The Shangyuan era was the Tang dynasty's reign period from 674 to 676. Therefore, he argued that Xue Rengui could not have taken part in the 676 Battle of Gibeolpo and that the battle actually occurred in 671, not 676.

Japanese scholar Furuhata Toru (古畑徹) and Chinese scholars Huang Wesse (黃約瑟, 1953?1993) and Liu Ju (劉矩) actively supported Ikeuchi’s view. Consequently, the Japanese and Chinese academic communities came to recognize the Battle of Gibeolpo as having taken place in 671.

Meanwhile, Chinese scholar Bai Genxing (拜根興) did not accept the Battle of Gibeolpo as occurring in 671 but questioned the Samguk Sagi records themselves. He emphasized the importance of the situation before the 675 Battle of Maesoseong and doubted the actual occurrence of the Battle of Gibeolpo.

Recently, domestic scholars influenced by Japanese and Chinese academia have begun to emerge. They argue that the Battle of Gibeolpo occurred not in November 676 but in September or November 675. The commonality of this new view is that there is an error in the year recorded in the Samguk Sagi and that the battle should be dated to 675. If so, the end of the Silla-Tang War and the unification of the Three Kingdoms should be readjusted to 675.

Japanese Historian: "Error in 671 Record"
Tang General Xue Rengui Allegedly Absent Due to Exile
Chinese Scholars Huang Wesse and Liu Ju Actively Agree
Some Domestic Scholars Also Consider "Possibility of 675"

The difference in views between domestic and international academia fundamentally stems from the credibility issues surrounding the records in domestic and Chinese historical texts. The question is whether one can trust the record that the world empire Tang was defeated by a peripheral small state (Silla).

Specifically, doubts arise from the whereabouts of Xue Rengui during the Silla-Tang War and the derived question of the actual occurrence of the Battle of Gibeolpo.

It is clear that both the Old Book of Tang and the New Book of Tang record that during the Shangyuan era, Xue Rengui was exiled to Xiangzhou (象州) in southern China (上元中坐事徙象州). However, neither record provides detailed circumstances explaining why he was exiled. The timing of the exile is also unclear. This contrasts with the clear record that in 670, after Xue Rengui was defeated in the Battle of Dafeichuan (大非川) against Tubo (吐蕃), he was dismissed (官軍大敗仁貴坐除名). In other words, the records vaguely state that he was exiled during the Shangyuan era due to "some matter (事)" without specifics.

It is difficult to unilaterally deny the detailed records in the Samguk Sagi based solely on the vague record of exile during the Shangyuan era without contextual explanation. Regarding this, American scholar John Jamieson presented an interesting view. He pointed out that records related to Tang generals who participated in the Silla-Tang War are missing. Liu Rengui (劉仁軌) left only victory-centered records, and Xue Rengui is ambiguously recorded as being in exile during the Shangyuan era. Moreover, the biographies of Li Jinxing (李謹行), Li Bi (李弼), and Yang Fang (楊昉) contain no articles related to the Korean Peninsula. Even Gao Kan (高侃), who participated alongside Li Jinxing, has no personal biography.

This suggests the possibility that articles related to the Silla-Tang War were intentionally omitted from the activities of these generals. Special attention should be paid to Liu Rengui, who held the highest rank among those deployed in the Silla-Tang War. He was the supervising national historian (監修國史) responsible for historical records at the time. It would have been difficult for the world empire Tang to record its defeat by a peripheral small state (Silla). Frankly, they would have wanted to erase it.

This tendency is also found among Baekje refugees who surrendered to Tang after Baekje's fall. For example, Buyeo Ryung (扶餘隆), the governor of Ungjin (熊津都督), has no biography. The biography of Heukchi Sangji (黑齒常之) lacks records from the Hanheng (咸亨) and Shangyuan (上元) eras, i.e., 670?676. Furthermore, the epitaphs of Buyeo Ryung and Heukchi Sangji contain no specific records of the Silla-Tang War period.

When Tubo's invasions intensified during the Yifeng era (儀鳳年間, 676?678), Wei Yuanchong (魏元忠) submitted countermeasures to the Tang emperor. At this time, Wei Yuanchong criticized Xue Rengui. The Old Book of Tang's biography of Wei Yuanchong states, "Rengui, since proclaiming his strength in the East Sea, has no achievements, and now is not punished, allowing his evil to worsen."

Interpreted, this means: "Earlier in 670, Xue Rengui suffered a great defeat in the Battle of Dafeichuan against Tubo. After being pardoned, he rejoined the Silla-Tang War but had no achievements. Yet he was not punished and his misdeeds only worsened."

Attention should be paid to the phrase "now is not punished." The exile of Xue Rengui to Xiangzhou occurred during the Shangyuan era, but Wei Yuanchong's criticism was during the Yifeng era. If Xue Rengui had truly been exiled to Xiangzhou during the Shangyuan era, Wei Yuanchong would not have needed to criticize him for not being punished during the Yifeng era. This suggests that Xue Rengui was sentenced to exile during the Shangyuan era but was not actually exiled.

World Empire Tang Defeated by Peripheral Small State
An Unwanted Fact, Intentionally Omitted
No Concrete Historical Records Exist

After Goguryeo's fall in 668, Xue Rengui was appointed Andong Protector (安東都護) overseeing the Andong Protectorate. When Tubo became aggressive in 670, he participated as the Grand Commander of the Nasado Army (邏娑道行軍大摠管) in the Battle of Dafeichuan but was heavily defeated and dismissed. When the Silla-Tang War intensified again, he was deployed as the Commander of the Gyerim Province Army (鷄林道行軍摠管) in the Battle of Seokseong in 671 but was defeated and returned to Tang. In 673, he engaged in creating Buddhist statues for the emperor and empress in Luoyang, then was redeployed to the Silla-Tang War. He participated in the Battle of Cheonseong in 675, was defeated, and was again deployed in the Battle of Gibeolpo in 676.

Before being sentenced to exile in Xiangzhou, Xue Rengui's final position was Commander of Gyerim Province, leading the conquest of Silla, i.e., the Silla-Tang War. The "some matter" that led to his exile sentence during the Shangyuan era can be seen as the defeats at the 675 Battle of Cheonseong and the 676 Battle of Gibeolpo.

Then how did Xue Rengui get opportunities for reappointment despite consecutive defeats? After the death of Tang Taizong, Xue Rengui served as Right General of the Imperial Guard (右領軍中郞將), responsible for palace security. Tang Gaozong resided at the Mannian Palace (萬年宮). One night, a sudden flood rushed through the Xuanwu Gate (玄武門). The guards fled in panic.

However, Xue Rengui judged the emperor was in danger. Risking his life, he climbed the gate and shouted loudly. The flood news spread inside the palace, prompting the emperor to quickly leave his chamber and seek higher ground. Eventually, water rose to the emperor's chamber. Because of this, Tang Gaozong deeply trusted Xue Rengui.

At that time, generals like Li Ji (李勣) and Su Dingfang (蘇定方), who had played active roles in the fall of Baekje and Goguryeo, had already died. There were not many generals available for large-scale expeditions under Tang Gaozong. Thus, Xue Rengui was given many chances to make a comeback.

When Xue Rengui returned after being sentenced to exile in Xiangzhou, Tang Gaozong did not reprimand him but said, "If it had not been for you at Mannian Palace then, I would have become a fish."

Professor Lee Sang-hoon, Department of Military History, Korea Military Academy