Battle of Baekgang (663): Tang and Silla Defeat Japan

The Battle of Baekgang, known in Japan as Hakusukinoe, was a naval battle fought in 663 at the mouth of the Baek River in south-western Korea. A Tang Chinese fleet, supported by the army of the Korean kingdom of Silla, destroyed a Yamato Japanese force sent to restore the fallen kingdom of Baekje. The defeat ended Japan’s military involvement on the Korean peninsula for nearly a thousand years and pushed the Yamato state into sweeping reforms.

Background: the fall of Baekje

In the 7th century the Korean peninsula was divided between three kingdoms: Goguryeo in the north, Baekje in the south-west and Silla in the south-east. Baekje had close ties with the Yamato court in Japan, sending it Buddhist teachers, scholars, craftsmen and, according to tradition, its first Buddhist images in the 6th century.

Silla, under pressure from both its neighbours, allied itself with Tang China in 648. In 660 a Tang army of about 130,000 men under Su Dingfang landed in Baekje, while the Silla general Kim Yu-sin advanced overland. The Baekje capital Sabi (modern Buyeo) fell in the seventh month of 660, and King Uija surrendered and was taken to China with his family and officials.

Baekje did not die quietly. Within weeks, loyalists led by the general Boksin and the monk Dochim rose against the occupiers and besieged the Tang garrison. They asked Yamato to send back Prince Buyeo Pung, a son of King Uija who had lived at the Japanese court for many years, to be their king, and to send an army with him.

Japan’s intervention

Empress Saimei and her son, Prince Naka no Oe, agreed. The court moved to Kyushu in 661 to direct the war, and the elderly empress died there that summer. Naka no Oe carried on, governing without formally taking the throne. Buyeo Pung was sent back to Korea with an escort of about 5,000 men and was proclaimed king by the rebels.

In 663 a much larger expedition followed: the Nihon Shoki, Japan’s official chronicle, records 27,000 men. By then, however, the Baekje movement was tearing itself apart. Pung suspected Boksin of plotting against him and had him killed, losing the movement’s most capable commander. Meanwhile Tang reinforcements under Sun Renshi arrived, and Silla’s King Munmu joined the campaign in person.

The Tang and Silla commanders decided to strike at Juryu, the rebels’ fortress near the coast. While Silla and Tang land forces closed in, the Tang commander Liu Rengui led a fleet of about 170 ships to the mouth of the Baek River to cut off the Japanese relief.

The battle

The two fleets met at the river mouth on the 27th day of the eighth lunar month of 663; in the Julian calendar this corresponds to early October. The Japanese ships arrived first and attacked, but were driven off by the Tang fleet drawn up in formation.

On the following day the Japanese commanders, according to the Nihon Shoki, agreed to attack again, confident that the enemy would give way. Their ships charged without a clear plan into the Tang line, which closed around them from both sides. The Japanese chronicle itself blames the disaster on the commanders and the Baekje king, who attacked without first studying the conditions or the enemy’s position. Many vessels were trapped and burned, and large numbers of men drowned. The Japanese general Echi no Takutsu is said to have fought until he was killed.

The Chinese histories describe four engagements, all won by the Tang, and say that some 400 Japanese ships were burned, with smoke and flame filling the sky and the sea turning red. Even allowing for exaggeration, both Chinese and Japanese accounts agree that the defeat was crushing. The Tang ships seem to have been larger and better organised, while the Yamato force was made up of contingents raised by regional chiefs with little unified command.

Key people

Liu Rengui (602-685) was the Tang commander who led the fleet at the river mouth; he later rose to the highest offices at court. Buyeo Pung, the would-be king of Baekje, escaped from the defeat and fled to Goguryeo. Prince Naka no Oe (626-672) directed the Japanese war effort and was crowned Emperor Tenji in 668. King Munmu of Silla (r. 661-681), then fighting on land, would later complete the unification of Korea under Silla. Buyeo Pung’s brother Buyeo Yung, taken to China in 660, served on the Tang side.

Consequences

The Baekje restoration collapsed. Juryu fortress surrendered in the ninth month of 663, and the remaining Japanese troops sailed home, taking many Baekje nobles and their families with them. Thousands of Baekje refugees settled in Japan, where they contributed to engineering, government, writing and Buddhism. The Nihon Shoki records groups of several hundred to more than two thousand Baekje men and women being granted land in the eastern provinces and in Omi in the following years, and some Baekje nobles were given Japanese court ranks matched to their former titles.

Tang and Silla turned next on Goguryeo, which fell in 668. Silla then fought Tang itself and by 676 held most of the peninsula south of the Taedong River.

In Japan, the defeat caused real fear of invasion. In 664 the court built the Mizuki, a great earthen dike with a moat to protect the government outpost at Dazaifu in Kyushu, and posted frontier guards (sakimori) and beacon stations on Tsushima, Iki and the Kyushu coast. Baekje engineers built mountain fortresses such as Ono and Kii in Kyushu in 665. In 667 Naka no Oe moved the capital inland to Otsu on Lake Biwa.

Legacy

The shock of Baekgang strengthened efforts, begun in the Taika Reform of 645, to build a centralised state on the Chinese model, with a census, land allocation and a conscript army. These culminated in the law codes of the early 8th century. Around this time the rulers of Yamato also began to call their country Nihon, “Japan”, and their monarch tenno, “emperor”.

Relations with Tang were repaired surprisingly quickly. Japan resumed sending missions to Tang China, and Chinese culture continued to flow into Japan, now increasingly directly rather than through Korea. Japan did not send an army to Korea again until Toyotomi Hideyoshi’s invasions of 1592.

Timeline

• 648: Silla forms an alliance with Tang China.
• 660, 7th month: Tang and Silla forces capture the Baekje capital Sabi; King Uija surrenders.
• 660-661: Baekje loyalists under Boksin and Dochim rise and appeal to Yamato for help.
• 661: Empress Saimei dies in Kyushu; Buyeo Pung returns to Korea with Japanese troops.
• 663, 6th month: Pung has Boksin killed; a large Japanese army sails for Korea.
• 663, 8th month, 27th-28th days: Tang fleet destroys the Japanese navy at the mouth of the Baek River.
• 663, 9th month: Juryu fortress falls; Japanese forces withdraw with Baekje refugees.
• 664-665: Japan builds the Mizuki dike and Korean-style forts in Kyushu.
• 667: The Japanese capital moves to Otsu.
• 668: Goguryeo falls to Tang and Silla; Naka no Oe is crowned Emperor Tenji.

Why it matters

Baekgang was one of the first great international battles in East Asian history, involving China, Korea and Japan at once. It decided the fate of Baekje, opened the way to Silla’s unification of Korea and confirmed Tang China as the dominant power of the region. For Japan, defeat abroad became a powerful push to reform at home, helping to shape the imperial state of the Nara period.