In 37 B.C. the power of the little kingdom of Sil-la began to be felt in surrounding districts and the towns of Pyön-han joined her standards. It was probably a bloodless conquest, the people of Pyön-han coming voluntarily into Sil-la. In 37 B.C. the capital of Sil-la, which had received the secondary name Keum-sŭng, was surrounded by a wall thirty-five _li_, twelve miles, long. The city was 5,075 paces long and 3,018 paces wide. The progress made by Sil-la and the evident tendency toward centralisation of all power in a monarchy aroused the suspicion of the king of Ma-han who, we must remember, had considered Chin-han as in some sense a vassal of Ma-han. For this reason the king of Sil-la, in 19 B.C., sent an envoy to the court of Ma-han with rich presents in order to allay the fears of that monarch. The constant and heavy influx into Sil-la of the fugitive Chinese element also disturbed the mind of that same king, for he foresaw that if this went unchecked it might mean the supremacy of Sil-la instead of that of Ma-han. This envoy from Sil-la was Ho-gong, said to have been a native of Japan. He found the king of Ma-han in an unenviable frame of mind and it required all his tact to pacify him, and even then he succeeded so ill that had not the Ma-han officials interfered the king would have had his life. The following year the king of Ma-han died and a Sil-la embassy went to attend the obsequies. They were anxious to find opportunity to seize the helm of state in Ma-han and bring her into the port of Sil-la, but this they were strictly forbidden to do by their royal master who generously forebore to take revenge for the insult of the preceding year. As this was the year, 37 B.C., which marks the founding of the powerful kingdom of Ko-gur-yŭ, we must turn our eyes northward and examine that important event. As the founder of Ko-gur-yŭ originated in the kingdom of Pu-yŭ, it will be necessary for us to examine briefly the position and status of that tribe, whose name stands prominently forth in Korean history and tradition. There were four Pu-yŭs in all; North Pu-yŭ, East Pu-yŭ, Chŭl-bŭn Pu-yŭ and South Pu-yŭ. We have already, under the head of the Tan-gun, seen that tradition gives to Pu-ru his son, the honor of having having been the founder of North Pu-yŭ, or Puk Pu-yŭ as it is commonly called. This is quite apocryphal but gives us at least a precarious starting point. This Puk Pu-yŭ is said by some to have been far to the north in the vicinity of the Amur River or on one of its tributaries, a belief which is sustained to a certain extent by some inferences to be deduced from the following legend.