Taking advantage of its weakness, the king of Yen began boldly and openly to seize upon Chō-sen territory, annexing thousands of square miles to his own domain. By a spasmodic effort, the successors of Ki Tsze again became ascendant, reannexing a large part of the territory of Yen, and receiving great numbers of her people, who had fled from civil war in China, within the borders of Chō-sen for safety and peace. Thus the spoiler was spoiled, but, later on, the kingdom of Yen was again set up, and the rival states fixed their boundaries and made peace. The Han dynasty in B.C. 206 claimed the imperial power, and sent a summons to the king of Yen to become vassal. On his refusing, the Chinese emperor despatched an army against him, defeated his forces in battle, extinguished his dynasty, and annexed his kingdom. One of the survivors of this revolt, named Wei-man, with one thousand of his followers, fled to the east. Dressing themselves like wild savages they entered Chō-sen, pretending, with Gibeonitish craft, that they had come from the far west, and begged to be received as subjects. Kijun, the king, like another Joshua, believing their professions, welcomed them and made their leader a vassal of high rank, with the title of ‘Guardian of the Western Frontier.’ He also set apart a large tract of land for his salary and support. In his post at the west, Wei-man played the traitor, and collecting a number of his former countrymen from the Yen province, suddenly sent to Kijun a messenger, informing him that a large Chinese army of the conquering Han was about to invade Chō-sen. At the same time, he suggested that he should be called to the royal side and be made Protector of the Capital. His desire being granted, he hastened with his forces and suddenly appearing before the royal castle, attacked it. Kijun was beaten, and fled by sea, escaping in a boat to the southern end of the peninsula. Wei-man then proclaimed himself King of Chō-sen, 194 B.C. He set out on a career of conquest and seized several of the neighboring provinces, and Chō-sen again expanded her boundaries to cover an immense area. Wei-man built a city somewhere east of the Ta-tong River. It was named Wang-hien. Two provinces of modern Corea were thus included within Chō-sen at this date. The new kingdom grew in wealth, power, and intelligence. Many thousands of the Chinese gentry, fleeing before the conquering arms of the Han “usurpers,” settled within the limits of Chō-sen, adding greatly to its prosperity. During the reign of Yukio (Chinese, Yow Jin), the grandson of Wei-man, he received a summons to become vassal to the Chinese emperor, who sublimely declared that henceforward the eastern frontier of China should be the Ta-tong River—thus virtually wiping out Chō-sen with a proclamation. In B.C. 109, a Chinese ambassador sailed over from China, entered the Ta-tong River, and visited Yukio in his castle. He plead in vain with Yukio to render homage to his master.