Goguryeo of The Three Kingdoms
Koguryo had developed out of the tribes of Manchuria into a state by the first century C.E. It had been described by the Chinese as filled with fierce warriors who had fought with the Chinese, the Xianbei, the Puyo, and others. Its own history states that the rule of its first king began in 37 B.C.E. Unlike similar beginning dates claimed by the other kingdoms, the date for Koguryo is probably fairly accurate.
Little is known about Koguryo from written records in the earliest periods, although they do appear often, but briefly, in Chinese records. Archaeology, confirmed by legend, tells more about early Koguryo. The most dramatic sites are the Koguryo tombs of royalty found in several locations in northeast China. There are also city walls and mountain fortresses that survive in part also located in various places in what is today China.
Koguryo had suffered severe losses in battles with the Xianbei during the reign of King Kogugwon (r. 331–371), but the kingdom rebounded and restructured its institutions under King Sosurim (r. 371–384), who made two important decisions in 372: He established a Buddhist temple in the name of the state, and he set up a Confucian academy. Both were giant steps in adopting Chinese culture. Koguryo also adopted a Chinese-style bureaucratic structure and proclaimed a new code of laws.
The building years of the late fourth century were followed by the expansion years of the early fifth century, when Koguryo reached its zenith. A monument to King Kwanggaeto (r. 391–413), dated 414, commemorated his accomplishments. The stele is about 18 feet tall and five feet square, and its 1,800 characters are still mostly legible. It stands in China on the north side of the Yalu River, just across the border from today’s North Korea, and there is an exact replica of it in the Independence Hall in South Korea.
It is a magnificent document, perhaps the oldest lengthy document that survives from early Korean history. It tells of the conquests of King Kwanggaeto, whose name means “expander and opener of territory.” According to the monument, he conquered 64 fortresses and 1,400 villages. His domain extended south along the east coast of Korea to a point about 100 miles from the Silla capital of Kyongju.
King Kwanggaeto’s successor, King Changsu (r. 413–491), who ruled for 79 years, was also noteworthy. His name aptly means “long life,” though most likely the title was given posthumously. (This was the case with later kings who were named posthumously according to their accomplishments, but were simply called “king” or “his majesty” when on the throne.)
Changsu was a diplomat and successfully kept at bay contending Chinese dynasties, thus enabling a period of peace and prosperity. It was in his reign that Koguryo moved its capital to the former Han dynasty trading center Lolang and renamed it Pyongyang. Later in his reign Koguryo captured the heart of the peninsula, the criti-cal Han River valley, by pushing Paekche farther south.
This was the height of Koguryo glory. In the Three Kingdoms Period control of the Han River valley was the single best measure of which kingdom was most powerful at the time.
Koguryo had been an ally of Silla against Paekche in the early fifth century, but as Koguryo grew stronger and pushed against its two southern neighbors, Silla broke its alliance with Koguryo and made an alliance with Paekche.
The ever-shifting alliances were one of the things that kept a balance among the triangular forces of the time and enabled three separate political entities to survive for three centuries in a relatively confined space.