rule of the vigorous Kitan chieftain, Opaochi, who, in 907, proclaimed himself Emperor of an independent kingdom with the dynastic title of Liao, said to mean "iron," and who at once entered upon that long course of aggression against China and encroachment upon her territory which was to result in the practical division of the empire between the two powers, with the Yellow River as boundary, Kʽai-fêng as the Chinese capital, and Peking, now for the first time raised to the status of a metropolis, as the Kitan capital. Hitherto, the Kitans had recognised China as their suzerain; they are first mentioned in Chinese history in A.D. 468, when they sent ambassadors to court, with tribute.
Turning now to China, the famous House of Sung, the early years of which were so full of promise of national prosperity, and which is deservedly associated with one of the two most brilliant periods in Chinese literature, was founded in 960. Korea was then forced, in order to protect herself from the encroachments of China, to accept the hated supremacy of the Kitans; but being promptly called upon to surrender large tracts of territory, she suddenly entered into an alliance with the Nü-chêns, who were also ready to revolt, and who sent an army to the assistance of their new friends. The Nü-chên and Korean armies, acting in concert, inflicted a severe defeat on the Kitans, and from
