The northern portion of Ham-gyŭng province was as yet but sparsely settled, and reports came in that the Ming people were coming in great numbers and settling there; so the king felt it necessary to do something to assert his rights. A great scheme for colonization was made and people from the southern part of the province were sent north to occupy the land. But there were two powerful Yŭ-jin chiefs across the Tu-man river who were constantly crossing and harrying the people along that border line. These were Ol-yang-t’ap and Hol-ja-on. It was not until the year 1436 that they were really silenced and then only after repeated and overwhelming victories on the part of the Korean forces. During these years thousands of people from the southern provinces were brought north by the government and given land in this border country. About this time a Japanese named Chŭng Seung was Daimyo of Tsushima. He sent fifty boats across to the Korean shore and the trade relations were revived which we may feel sure had been sadly interrupted by the long period of piratical raids. The government made these people a present of 200 bags of rice and beans. Sixty “houses” of people also came from that island and asked to be allowed to live in the three ports, Ch’ep’o, Yŭm-p’o and Pu-san-p’o. The king gave his assent and from that time until about the present day, with only temporary intermissions, the Japanese have resided in one or other of these three places, although Pu-san (Fusan) has always been the most important of them. In the year 1443 the custom of giving the Daimyo of Tsushima a bonus of 200 bags of grain a year was instituted. The number of trading boats that could come was strictly limited by the Korean government to fifty, but in extreme cases where sudden need arose through piratical raids or other cause the number could be increased. This custom continued without interruption until 1510.