The first century of the dynasty saw the sowing of the seeds of evil which were to spring up and bear such disastrous fruit; but the nation was a virile one as yet, and under stress of circumstances could summon a formidable army in her own defence. This was seen when, early in the eleventh century, the semisavage people of Kitan in the north one of those hordes which periodically have swarmed southward from the Manchurian plains came across the Yalu, expecting to carry everything before them. In this they were sadly disappointed ; for though at the first considerable disorder existed in the country, the people rallied, put an army of some two hundred thousand men into the field, and soon had the half-naked plunderers in full retreat. Kitan tried for a time to assert herself in the peninsula, but never with success. She built a bridge across the Yalu and successfully defended it, but Koryu retaliated by building a wall clear across the peninsula from the Yellow Sea to the Japan Sea. Remains of this can be seen to-day in the vicinity of Yong-byun. It was twenty-five feet high and two hundred miles long. This period marks the summit of Koryu's power and wealth. She had reached her zenith within a century and a quarter of her birth, and the next three centuries are the story of her decline and fall. To show the power that Buddhism exercised at this time we have but to give a single paragraph of detail.
In 1065 the King's son cut his hair and became a Buddhist monk. A law was promulgated forbidding the killing of any animal for a period of three full years. A monastery was built in the capital, consisting of twenty-eight hundred kan, each eight feet square. This gave a floor space of nearly one hundred and eighty thousand square feet, the equivalent of a building a third of a mile long and a hundred feet wide. It required twelve years to complete it. A magnificent festival marked its opening, at which thousands of monks from all over the country participated. The feasting lasted five days. There was a magnificent awning of pure silk, which formed a covered passage-way from the palace to this monastery. Mountains and forests were
