The probabilities are that the people of the old Fuyu race, descendants of the tribes of Kokorai, as the more vigorous stock, had already so far supplanted the old aboriginal people inhabiting Southern Corea as to make conquest by Wang, who was one of their own blood, easy. This is shown in a series of maps representing the three kingdoms of Corea from 201 to 655 A.D., by the Japanese scholar Otsuki Tōyō. At the former date the Kokorai people beyond that part of their domain conquered by China have occupied the land as far south as the Han River, or to the 37th parallel. Later, Shinra, in 593, and again in 655, backed by Chinese armies, had regained her territory a degree or two northward, and in the eighth and ninth centuries, acting as the ally of China, ruled all the country to the Tumen River. Yet, though Shinra held the land, the inhabitants were the same, namely, the stock of Korai, ready to rise against their rulers and to annihilate Shinra in a name and monarchy that had in it nationality and the prestige of their ancient freedom and greatness.
Thoroughly intent on unifying his realm, Wang chose a central location for the national capital. Kion-chiu, the metropolis of Shinra, was too far south, Ping-an, the royal seat of old Korai, was too far north; but one hundred miles nearer “the river” Han, was Sunto. This city, now called Kai-seng, is twenty-five miles from Seoul and equally near the sea. Wang made Sunto what it has been for over nine centuries, a fortified city of the first rank, the chief commercial centre of the country, and a seat of learning. It remained the capital until 1392 A.D. Wang-ken or Wang, the founder of the new dynasty under which the people were to be governed for over four hundred years, was an ardent Buddhist. Spite of his having put the monk to death to further personal ends, he became the defender of the India faith and made it the official religion. Monasteries were founded and temples built in [[67]]great numbers. To furnish revenues for the support of these, tracts of land were set apart as permanent endowment. The four centuries of the house of Korai are the palmy days of Corean Buddhism.
From China, which at this time was enjoying that era of literary splendor, for which the Sung dynasty was noted, there came an impulse both to scholastic activity and to something approaching popular education.
The Nido, or native syllabary, which had been invented by Chul-chong, the statesman of Shinra, now came into general use. While Chinese literature and the sacred books of Buddhism were studied in the original Sanscrit, popular works were composed in Corean and written out in the Nido, or vernacular syllables. The printing press, invented by the Sung scholars, was introduced and books were printed from cut blocks. The Japanese are known to have adopted printing from Corea as early as the twelfth century, when a work of the Buddhist canon was printed from wooden blocks. “A Corean book is known which dates authentically from the period 1317–1324, over a century before the earliest printed book known in Europe.” The use of metal type, made by moulding and casting, is not distinctly mentioned in Corea until the year 1420, and the invention and use of the Unmun, a true native alphabet, seems to belong to the same period. The eleven vowels and fourteen consonants serve both as an alphabet and a syllabary, the latter being the most ancient system, and the former an improvement on it.
The unifier of Corea died in 945 and was succeeded by his son Wu. Fifteen years later the last of the five weak dynasties that had rapidly succeeded each other in China, fell. The Chinese emperor proposing, and the Corean king being willing, the latter hastened to send tribute, and formed an alliance of friendship with the imperial Sung, who swayed the destinies of China for the next 166 years (960–1101).
Korai soon came into collision with the Kitans in the following manner. The royal line of united Corea traced their descent directly from the ancient kings of Kokorai, and therefore claimed relationship with the princes of Puhai. On the strength of this claim, the Koraian king asserted his right to the whole of Liao Tung, which had been formerly held by Puhai. The Kitans, having matters of greater importance to attend to at the time, allowed its temporary occupation by Korai troops. Nevertheless the king [[68]]thought it best to send homage to the Kitan emperor, in order to get a clear title to the territory. In 1012 he despatched an embassy acknowledging the Kitan supremacy. This verbal message did not satisfy the strong conqueror, who demanded that the Koraian king should come in person and make obeisance. The latter refused. A feud at once broke out between them, which led to a war, in which Korai was worsted and stripped of all her territory west of the Yalu River.
Palladius has pointed out the interesting fact that a little village about twenty miles north of Tie-ling, and seventy miles north of Mukden, called Gauli-chan (Korai village) still witnesses by its name to its former history, and to the possession by Corea of territory west of the Yalu.
The Kitans, not satisfied with recovering Liao Tung, crossed the river and invaded Korai, in 1015. By this time a new nation, under the name of Nüjun or Ninchi, had formed around Lake Hanka, in part of the territory of extinct Puhai. With their new frontagers the Koraians made an alliance “as solid as iron and stone,” and with their aid drove back the Kitan invaders.
Henceforth the boundaries of Corea remained stationary, and have never extended beyond the limits with which the western world is familiar.
An era of peace and prosperity set in, and a thriving trade sprang up between the Nüjun and Korai. The two nations, cemented in friendship through a common fear of the Kitans, grew apace in numbers and prosperity.