It was about this time that Kitan changed its name to Yo. She at once sent an envoy announcing the fact. These were the golden days of Koryŭ’s relations. The Yŭ-jin tribe of To-ryŭng-ko-do-wha came and swore allegiance as also did the Chang-man and Tu-hul tribes. A few years later a Japanese ruler named Sal-ma sent gifts to the Koryŭ court as also did the people of Tsushima. During the latter years of this reign the Kitan people were induced to break down the bridge across the Yalu but it was done only by sending an abject letter in which the Koryŭ king said “As all the world is yours and all the people in the world belong to you, you have no need of a bridge to bind us to you.” In 1077 an envoy came from the Emperor of China (Sung dynasty) asking aid against the Kitan. The king might well have turned and answered that as the Emperor had remained deaf to Koryŭ’s entreaties for help so now Koryŭ would decline to respond. But he did nothing of the kind; this opportunity to reëstablish friendly relations with China was hailed with delight by all classes. The king, though ill, was carried on his bed outside the city walls to meet this welcome messenger. The latter was treated royally and was loaded with so many gifts that he could not take them back with him. He had no intention, however, of leaving them entirely, for he sold them and took the money instead. This sort of thrift was something new to the Koreans and they showed their disgust by ridiculing him; and when he left they spat upon the ground in token of their contempt. We are not told that Koryŭ gave the aid requested. And yet the friendly relations were continued, as is seen from the fact that in 1079 the emperor sent physicians and medicines to Koryŭ. We have here the first definite mention of gold mining in the statement that the people of Hong-wŭn dug a hundred ounces of gold and a hundred and fifty ounces of silver, which they sent to the king. He graciously gave it back to them. In 1084 the king died and his adopted son Hun, posthumous title Sun-jong, came to the throne; but he died almost immediately and was succeeded the same year by his younger brother Un, posthumous title Sŭn-jong. When the messenger announcing this arrived at the gates of the Kitan capital he was refused entrance, for they said there must be some underlying cause for the sudden death of king Sun-jong.