Three states, one peninsula
The Three Kingdoms period of Korea is conventionally dated from the first century BCE to 668 CE. In that time three states, Goguryeo in the north, Baekje in the southwest and Silla in the southeast, competed for territory, trade and prestige, while the smaller Gaya states along the south coast were absorbed one by one. The name is borrowed from the Chinese Three Kingdoms of the third century CE, and it is a convenience. Korean states of the period were not equal in strength at all times, and the period also had other actors, such as Buyeo and Gaya.
The main narrative sources are the Samguk sagi, compiled in 1145 by Kim Busik, and the Samguk yusa of the thirteenth century. Both were written long after the events and draw on earlier lost texts. They give traditional founding dates of 57 BCE for Silla, 37 BCE for Goguryeo and 18 BCE for Baekje. Most historians treat these as legendary or semi-legendary, as the real consolidation of each state likely took place a few centuries later. Chinese histories and inscriptions provide an important check.
Goguryeo
Goguryeo arose in the mountainous region around the middle Yalu River and the Liaodong area. It was a military state that fought repeatedly with Chinese dynasties and with nomadic neighbours. Its early capital was at Guknae, near modern Ji’an in China, and in 427 the capital moved to Pyongyang under King Jangsu.
The most celebrated ruler is Gwanggaeto the Great, who reigned from 391 to 413. A huge stone stele, raised by his son in 414 near Ji’an, records his campaigns, and its interpretation, especially passages about Japan and Baekje, remains debated. Goguryeo is also famed for its resistance to the Sui dynasty: Sui invasions in the early seventh century failed, including a major defeat on the Salsu River in 612, and later Tang attacks were also repulsed for a time. Its tombs, many with wall paintings of hunting, daily life and cosmic imagery, form an extraordinary record and are listed as World Heritage.
Baekje
Baekje emerged around the Han River, in the area of modern Seoul, where its first capital Wirye or Hanseong lay. It built close ties with the Chinese southern dynasties and became a major cultural intermediary with Japan. After Goguryeo seized the Han River region in 475, Baekje moved its capital south to Ungjin, now Gongju, and in 538 to Sabi, now Buyeo.
The tomb of King Muryeong, found intact at Gongju in 1971, is one of the major discoveries of Korean archaeology. It contained gold ornaments and an epitaph stone that gives his dates, 462 to 523, a rare firm anchor. Another famous find is a gilt-bronze incense burner discovered at Neungsan-ri near Buyeo, a masterpiece of sixth- or seventh-century metalwork. Baekje craftsmen, scholars and monks are credited with transmitting Buddhism and other skills to Japan, although the traditional dates for the first Buddhist mission, 538 or 552, are themselves contested.
Silla
Silla began as a small state in the Gyeongju basin, probably the most isolated of the three from Chinese influence at first. It developed a hierarchical social structure known as the bone-rank system, which determined which families could hold office and even what they could wear. Its early royal tombs at Gyeongju, built of stone and earth, held remarkable gold crowns, belts and jewellery. These show links to the steppe world and to Central Asian styles, a sign of wide trade connections through the Silk Road trade routes.
Silla adopted Buddhism officially in the sixth century, traditionally in 527 after the martyrdom of an official named Ichadon, though such stories were embellished later. It also absorbed the Gaya states. Queen Seondeok, who ruled from 632 to 647, is associated with the construction of Cheomseongdae, an astronomical observatory in Gyeongju, although the dating of the structure to her reign relies on later tradition. The Hwarang, an elite youth organisation, is another famous Silla institution, with many details uncertain.
Rivalry and unification
Alliances shifted constantly. Baekje and Goguryeo were sometimes allied, sometimes enemies, and Silla at times sided with each. Pressured by both, Silla sought help from the Tang dynasty, which was by then a Tang cosmopolitan empire looking to expand in the northeast. In 660 a Silla-Tang force defeated Baekje, and in 668 Goguryeo fell after years of Tang campaigns and internal splits in its leadership.
The result was not simply a Silla victory. Tang forces had intended to rule the peninsula, and Silla fought them in the following years, driving them out of most of the area by 676. The unified state that emerged is called Unified Silla. It controlled only the area south of roughly the Taedong and Wonsan line, while the northern territory of Goguryeo was later taken up in part by the state of Balhae.
Cultural achievements
The era left lasting marks on Korean culture:
- Buddhism and art. All three kingdoms adopted Buddhism between the late fourth and sixth centuries, with Goguryeo traditionally in 372 and Baekje in 384.
- Metalwork. Gold, gilt-bronze and ironworking reached high levels, and Gaya iron was widely traded.
- Writing and learning. Chinese characters and the Confucian classics were studied, and methods of writing Korean with Chinese characters began to develop.
- Architecture and astronomy. Fortress cities, pagodas, tombs and observatories show advanced engineering.
- Influence abroad. Korean craftsmen, scholars and technology were important in the rise of the Yamato state in Japan.
Throughout, the Chinese dynastic timeline is a useful reference for the many Chinese records on which our knowledge of the Three Kingdoms partly depends, and it also shows how much Korean history was bound up with events in China.