Free A History of Korea by Jinwung Kim

large tribal enclaves: Sono-bu (or Piryu-bu), Ch ŏ llo-bu (or Y ŏ nna-bu), Sunno-bu (or Hwanna-bu), Kwanno-bu (or Kwanna-bu), and Kyeru-bu. In 37 BC Chumong and his Kyeru-bu people, the so-called horse-riding warriors, took political leadership in the confederated kingdom, heralding the beginning of “New Kogury ŏ .”
    At first the Kogury ŏ people were a hunting tribe that had settled in the mountainous regions of southern Manchuria. Thus Kogury ŏ had to break out of these regions and make inroads into the south, with its vast stretches of plains. In AD 3 Kogury ŏ transferred its capital from Cholbon (Hwanin) to Kungnae-s ŏ ng on the Yalu. Defended by Hwando-s ŏ ng in the rear and fronted by the Yalu River, the new capital was a natural stronghold.
    By the first century AD Kogury ŏ was firmly established as a state power. King T’aejo (53–146?) vigorously expanded the Kogury ŏ territory through aggressive military activities allowing Kogury ŏ to exact tribute from its neighbors. T’aejosubjugated Okch ŏ to secure a base in the rear and consolidate the material foundations by acquiring a tributary state. He also actively took the offensive against the Chinese, attacking the Liaodong region east of the Liao River and the Chinese commandery of Nangnang. T’aejo and his successors then absorbed the newly won resources and manpower into Kogury ŏ , thus continuing Kogury ŏ ’s territorial expansion. Domestically T’aejo established the permanent right to the throne by the Ko house (clan) of the Kyeru-bu lineage, and thus he came to be called T’aejo, or the founder-king.
    During the reign of King Kogukch’ ŏ n (179–197) the monarch’s authority became further consolidated and the kingdom’s political structure became increasingly centralized. First, the five original tribal enclaves from the earlier, traditional society were reorganized into five centrally ruled districts termed
pu,
or provinces, and given names connoting the directions north, south, east, west, and center; these were the administrative units of the capital and its neighboring areas. Chieftains of the former enclaves were integrated into the central aristocracy. Second, royal succession changed from a brother-to-brother pattern to one of father to son, representing a growth in monarchical power. Third, it became established practice for queens to be taken from the My ŏ ngnim house of the Ch ŏ llo-bu (or Y ŏ nna-bu) lineage, which allowed the king to secure a permanent ally against potential political centers that might oppose the strengthening of royal power. Fourth, King Kogukch’ ŏ n appointed as prime minister an obscure individual named Ŭ lp’aso to enforce the
chindaep ŏ p,
or relief loan law, which prevented poor peasants from becoming slaves of the aristocracy and enabled them to borrow grain from the state during the spring famine season and repay it at low interest after the autumn harvest.
    As Kogury ŏ achieved domestic stability, it gained great momentum for waging military campaigns against the Chinese. Repeated Chinese counterattacks failed to crush the elusive warriors of Kogury ŏ , who were well protected in their mountainous habitat and highly mobile as a result of long experience with a hunting economy. In the first such campaign, in 242 King Tongch’ ŏ n (227–248) attacked Xianping(S ŏ anp’y ŏ ng in Korean), a Chinese strategic county at the estuary of the Yalu, in order to cut off the land route linking China proper with its Nangnang Commandery. The Chinese Wei dynasty immediately retaliated. The Wei (222–280) was one of three dynasties that had been established in China after the Han empire fell in 220 and was the closest to Kogury ŏ . In 244, with the intention of succeeding the Han empire in Nangnang, Wei sentan invading force led by Guanqiu Jian to Kogury ŏ , capturing Hwando-s ŏ ng near the capital of Kungnae-s ŏ ng. When Wei’s military forces, led by Wang Qi, invaded Kogury ŏ again the