Before his accession to the throne he had succeeded in putting down the Japanese pirates, at least for the time. He now placed high military and naval officials at all the great southern ports, who offered the people still further protection. He also set aside the three ports of Ch’e-p’o, Yŭm-p’o and Pu-san-p’o (Fusan) as places where Japanese envoys and trading parties might be entertained. At these places he built houses for the accommodation of such guests. King T'ă-jo had a numerous family. By his first Queen, Han, he had six sons, of whom the second and the fifth later became Kings of Cho-sŭn, with the posthumous titles of Chöng-jong and T‘ă-jong respectively. By his second Queen, Kang, he had two sons, both of whom aspired to the crown but without hope. They were named Pang-sŭk and Pang-bon. Their ambition led them astray, for now in the sixth year of the reign they conspired to kill their two rival half-brothers and so prepare the way for their own elevation. They secured the services of two assassins who made the attempt, but being foiled they lost their heads. It was well known that the two princes were at the bottom of the plot, and the king, knowing that even he could not protect them from justice, advised them to make good their escape. They fled but were caught just outside the West Gate and put to death. The courtiers were all homesick for Song-do and the king himself probably missed many of the comforts which he had there enjoyed. Merchants had not as yet come in large numbers to the new capital and the number of houses was comparatively small. It must be noticed that with the change of dynasty it was taken for granted that the citizens of the old capital were loyal to the fallen dynasty and so the people of Song-do were not allowed to move to Seoul in large numbers. That city was reserved as the residence of the friends of the new regime. Song-do has ever been considered less loyal than any other city in the country and the rule has been that no native of that city could hold an important office under the present government. But at first, the new capital was hardly as pleasant a place to live as the old, and so the king gave the word and the whole court moved back there for a time.