King Seong of Baekje

Seong was the twenty-sixth king of Baekje, one of the three kingdoms that shared the Korean peninsula in the sixth century, alongside Goguryeo in the north and Silla in the south-east. He came to the throne in 523 after the death of his father, King Muryeong, whose tomb in Gongju is one of the most famous archaeological discoveries in Korea.

Korea’s oldest surviving history, the Samguk sagi (1145), describes him as a man of outstanding intelligence who could make decisions, and says that the people of the country called him Seong, “the Sage”. Japanese chronicles call him Seongmyeong-wang, the “Sage and Bright King”. Some historians connect this name with the Buddhist ideal of the wheel-turning king, a ruler who governs by Buddhist law.

His reign of thirty-one years can be divided into two halves. In the first he rebuilt the kingdom at home, moving the capital and reorganising government. In the second he tried to restore Baekje’s old heartland on the Han River, an effort that ended with his death in battle in 554.

In 475 Goguryeo had captured Baekje’s first great capital, Hanseong, near modern Seoul, and killed its king. The survivors fled south to Ungjin (modern Gongju), a small town protected by hills and the Geum River. It was a good hiding place but a cramped capital.

In 538 Seong moved the court further down the Geum River to Sabi (modern Buyeo), where a broad plain gave room for a planned city and the river gave access to the Yellow Sea. A mountain fortress was built on Mount Buso above the river, and an outer earthen wall, the Naseong, protected the city on its landward side. Inside were palaces, markets, residential wards and Buddhist temples such as Jeongnimsa, whose elegant five-storey stone pagoda still stands.

At the same time Seong renamed the kingdom Nambuyeo, “Southern Buyeo”. Buyeo was an ancient kingdom in Manchuria from which both Baekje’s and Goguryeo’s royal families claimed descent. By using this name Seong reminded everyone that Baekje’s kings came from a line as ancient and noble as Goguryeo’s.

Seong kept up close contact with the Liang dynasty, which ruled southern China from its capital Jiankang (modern Nanjing). Baekje envoys brought gifts and received titles from the Liang emperor. In 541, the Samguk sagi records, Seong asked for a specialist on the Confucian classics, commentaries on the Nirvana Sutra, craftsmen and painters, and the Liang court sent them.

Baekje passed much of this knowledge on to the Wa court in Japan. Seong sent a gilt-bronze Buddha image, banners and sutras, which Japanese tradition remembers as the official introduction of Buddhism to Japan. Later he sent teams of specialists, scholars of the classics, doctors, calendar experts, diviners and musicians, who served for a period and were then replaced by others.

Because of these exchanges, Baekje was a hub in a network linking the Yangtze valley, the Korean peninsula and the Japanese islands. Temples, roof tiles, writing, medicine and the Chinese calendar all travelled along this route in Seong’s time.

Historians see the move to Sabi as a planned political project rather than a flight. The Ungjin period had begun in chaos: after 475 several kings were murdered by powerful nobles, and the throne depended on aristocratic clans who had settled in the Gongju area. Seong’s father Muryeong restored stability; Seong used the new capital to reshape power. A new city meant new land, new offices and the chance to favour families who supported the king, notably the Sa (沙) clan associated with the Sabi region.

Korean historians attribute a series of reforms to this period. Central government was organised into twenty-two departments, twelve serving the palace and ten handling state affairs. Officials were ranked in a sixteen-grade system distinguished by the colour of their robes. The capital was divided into five districts (bu), and the provinces into five regions (bang), each with a fortress-based administration controlling commanderies below it.

Our knowledge of these institutions comes largely from Chinese histories of the Zhou and Sui dynasties, which describe Baekje as it was in the later sixth century, so it is not certain that every element was created under Seong. What is clear is that the Sabi period produced a more centralised monarchy, and that its planned capital, with its fortress, city wall and temples, became the model for the rest of Baekje’s history until 660.

Buddhism was part of this programme. Temples in the capital served as centres of learning and royal ritual. A later temple record says that the monk Gyeomik travelled to India and returned in 526 with Vinaya (monastic discipline) texts, which were then translated in Baekje; this account survives only in a much later source and is treated with caution by historians, but it reflects Baekje’s reputation as a centre of disciplined Buddhist scholarship.

Liang was ruled for most of Seong’s reign by Emperor Wu (r. 502–549), a devout Buddhist who four times gave himself to a temple as a servant and had to be “ransomed” by his officials. Baekje’s interest in Liang was partly cultural and partly strategic: Liang was the great rival of the northern dynasties that bordered Goguryeo. In 524 the Liang emperor granted Seong the title of general and King of Baekje, confirming the recognition already given to Muryeong.

A rare picture of these contacts survives in the Portraits of Periodical Offering, a scroll of foreign envoys painted in the 520s–530s by Xiao Yi, a Liang prince who later became emperor. A Song-dynasty copy shows a Baekje envoy alongside envoys from Persia, the Hephthalites of Central Asia, Kucha and Wa, with short descriptions of each country. For the Liang court, Baekje was one of many kingdoms whose visits proved the emperor’s universal virtue; for Baekje, the journey to Jiankang was a way into the most sophisticated culture in East Asia.

The relationship ended in tragedy. In 548 the general Hou Jing rebelled and besieged Jiankang, and Emperor Wu died in 549. The Samguk sagi relates that a Baekje embassy, unaware of the rebellion, arrived that year to find the palace in ruins, and wept outside the palace gate, moving passers-by to tears; Hou Jing then detained the envoys until his fall. Liang never recovered, and Baekje later turned to the Northern Qi, Chen and eventually Sui.

Since 433 Baekje and Silla had been allies against Goguryeo. In the 540s Goguryeo was weakened by a succession struggle, and in 548 Silla helped Baekje repel a Goguryeo attack on Doksan fortress. In 551 Seong led a joint offensive with Silla and Gaya: Baekje recovered the lower Han River basin, including its old capital region, while Silla under King Jinheung took the upper reaches.

The victory did not last. In 553 Silla turned on its ally, seized the lower Han basin and set up a new province there, Sinju. According to the Samguk sagi, a daughter of Seong was married to the Silla king in the same year, which suggests that diplomacy continued even as the alliance collapsed. For Silla, control of the Han valley meant direct access to the Yellow Sea and to China, a prize that would prove decisive in the next century.

In 554 Seong’s son, Prince Yeochang, led Baekje forces with Gaya contingents (and, according to the Nihon shoki, some Wa troops) against the Silla fortress of Gwansan, near modern Okcheon. After early successes, Silla reinforcements under Kim Muryeok arrived. Seong set out at night with a small escort of about fifty men to join his son and was ambushed and killed at a place called Gucheon. Silla records claim that 29,600 Baekje soldiers died, together with the king and four of his highest ministers. The Nihon shoki adds that his head was buried under the steps of a Silla government building.

The defeat ended the Baekje–Silla alliance for good. For the next century Baekje and Silla fought almost continuously, until Silla, allied with the Tang empire, destroyed Baekje in 660.

Seong’s reign almost exactly overlaps with that of Justinian I in Constantinople (527–565). While Seong was planning Sabi, Justinian’s commission compiled the Code, Digest and Institutes of Roman law (529–534) that later became known as the Corpus Juris Civilis, and after the Nika riots of 532 he rebuilt Hagia Sophia, consecrated in 537. In 541–542 a devastating plague, the “Plague of Justinian”, swept the Mediterranean. Further east, Khosrow I became king of Sasanian Persia in 531 and reformed its taxes and army.

These distant worlds were faintly connected. The Liang scroll of foreign envoys shows Baekje and Persian envoys in the same imperial collection, and silk, glass and ideas moved along land and sea routes that linked Jiankang with Central Asia, Persia and India. The Liang emperor’s Buddhism drew on Indian and Central Asian monks, and texts that reached Liang could arrive in Baekje within a generation.

Much closer, Seong’s neighbours were also transforming themselves. In Silla, King Beopheung issued a law code in 520 and officially accepted Buddhism in 527 or 528 after the martyrdom of Ichadon; Silla annexed Geumgwan Gaya in 532, and King Jinheung (r. 540–576) expanded in every direction. In Japan, the Iwai rebellion in Kyushu (527) and the reign of Emperor Kinmei (traditionally 539–571) were the setting for the arrival of Baekje’s Buddhism, and a generation later the Soga clan built Asuka-dera with Baekje craftsmen.

In India the Gupta age had passed its peak, though its science lived on: Aryabhata’s astronomical treatise had been written in 499. In Italy Benedict of Nursia founded his monastery at Monte Cassino around 529, the same era in which Baekje’s monks were building a tradition of monastic discipline. Seen together, the first half of the sixth century was an age in which rulers from Constantinople to Sabi used law, monumental building and religion to strengthen their states.

Seong’s son Chang, known as King Wideok, reigned for more than forty years after the disaster. Near the royal tombs at Neungsan-ri, just outside Sabi’s city wall, archaeologists found a temple site where, in 1993, the magnificent Gilt-bronze Incense Burner of Baekje was excavated. In 1995 a granite relic container was found beneath the base of the temple’s wooden pagoda. Its inscription says that in the thirteenth year of King Chang (567) a princess, the king’s sister, offered relics there. Many scholars interpret the temple as a memorial foundation for the dead King Seong.

The city Seong founded remained Baekje’s capital until 660. Its remains, including Busosanseong, the Naseong wall, Jeongnimsa and the Neungsan-ri tombs, are now part of the UNESCO World Heritage Site “Baekje Historic Areas” (2015), together with sites in Gongju and Iksan. The Baekje Cultural Festival held in Buyeo and Gongju celebrates this heritage.

In Japan Seong is remembered as the king who sent Buddhism. A later tradition associated with Hōryū-ji holds that its Guze Kannon statue was made in his likeness; such stories are not contemporary evidence, but they show how strongly Baekje was associated with the beginnings of Japanese Buddhism.

538 or 552? The year when Seong’s mission brought Buddhism to Japan is famously uncertain. The Nihon shoki (720) places it in the thirteenth year of Emperor Kinmei, corresponding to 552, and describes a court debate in which Soga no Iname supported the new faith while the Mononobe and Nakatomi opposed it. Two other early Japanese texts, the Jōgū Shōtoku hōō teisetsu and the Gangōji garan engi, give a year corresponding to 538. Many Japanese textbooks and scholars favour 538, partly because the Nihon shoki is known to have adjusted its chronology and because 552 was traditionally calculated as the start of the “latter age of the Dharma”, which may have made it attractive to later compilers. Others point out that both dates rest on later texts, that the two sources for 538 have their own problems, and that Buddhism had almost certainly reached Japan earlier through immigrants from the peninsula. The dispute concerns Japanese chronology rather than national pride, but it shows how Korean and Japanese sources must be read together.

Gaya and the “Mimana” question. The Nihon shoki records meetings convened by Seong at Sabi in the 540s with representatives of the Gaya states and envoys associated with Wa, which it calls conferences to “restore Mimana”. Pre-war Japanese historiography read these passages as proof of a Yamato colony in southern Korea (the “Mimana Nihonfu”). Most Korean historians, and many Japanese historians today, read them instead as Baekje-led diplomacy aimed at drawing the Gaya states into Baekje’s orbit before Silla absorbed them, with the “Wa officials” in Gaya best understood as envoys or agents rather than colonial governors. The debate turns on how far the Nihon shoki’s eighth-century imperial framing distorts the underlying Baekje records it drew on.

Betrayal or strategy? Korean popular narratives often describe Silla’s seizure of the Han valley in 553 as a “betrayal” and Seong as a tragic hero. Historians caution that this reflects the viewpoint of the Baekje annals and of later sympathies. From Silla’s perspective, the Han basin was the key to direct contact with China and a legitimate prize of a war in which Silla had fought as an equal partner; secret negotiations with Goguryeo, which some scholars suspect, would also have been ordinary sixth-century statecraft. Similarly, the view that Seong’s final campaign was reckless is balanced by the argument that Baekje’s nobility, not the king alone, pushed for war, and that Seong’s death strengthened the aristocracy at the expense of the throne.

The main written sources for Seong are the Baekje and Silla annals of the Samguk sagi, compiled in Goryeo in 1145; the Chinese dynastic histories of the Liang, Zhou and Sui; and the Nihon shoki. The Samguk sagi’s Baekje annals for his reign are brief and concentrate on diplomacy and war. Chinese histories supply titles and descriptions of institutions. The Nihon shoki contains by far the most detail about Baekje in the 540s and 550s, apparently drawing on lost Baekje histories such as the Baekje bongi, but embeds this material in an imperial ideology that presents Baekje as a tributary of Yamato.

Archaeology now provides an independent check. Excavations at Busosanseong, the Naseong wall, Jeongnimsa, the Gwanbuk-ri area (a candidate for the royal palace) and the Neungsan-ri temple and tombs have clarified the plan and dating of Sabi. Wooden tablets (mokgan) from Sabi-period sites reveal administrative practices, and the 567 reliquary inscription is a contemporary text that confirms the reign of King Chang. Comparisons of roof tiles and temple plans with sites in Nanjing and in the Asuka region of Japan make the Liang–Baekje–Wa network visible in material form.

Where Seong himself was buried is uncertain. The tombs at Neungsan-ri are royal stone-chamber tombs of the Sabi period, and one of them is often proposed as his, but no inscription has confirmed this. Unlike his father Muryeong, whose tomb was identified by its epitaph, Seong remains known mainly through what others wrote about him.