Kim Tong-Jung is a chief of Sambyulcho(三別抄), which resisted to death to the allied forces between Koryo and Mongo. In Cheju-island, Kim Tong-Jung was not just a historical man ; he seemed to be a village god and also a popular hero who appeared in some legends. Thus, if you look synthetically into historical documents, myths of village gods, legends, you can clearly find out the actual fact of the tales about Kim Tong-Jung.
According to historical documents, Sambyulcho kept friendly realations with inhabitants in Cheju-island : Cheju people helped sambyulcho go into Cheju-island, and supported them. Sambyulcho didn't plunder villages and didn't govern oppressively while they stationed themselves in Cheju-island. That is, Kim Tong-Jung seemed to be an affirmative popular-hero.
In addition, Kim Tong-Jung was described as a brave commander who helped inhabitants, so he was considered as a god and was enshrined in some villages. On the contrary, he had a negative image ; he was reported to be conquered by three commanders from China, because he desired to govern Cheju-island. But, nevertheless, even the latter material value him affirmative, and his good image appeared better in legends. Legends said he was born holily like deities. The birth means growing to be a King. And also he was described as a baby-commander who should build a new future world, this means he was a messiah to Cheju people.
Kim Tong-Jung appeared mainly to be affirmative from the tales about him, and also you can find some material in which he appeared to be negative. Until now, some researchers thought that he was a negative person, because he was an alien ; he was thought as a kind of a potential trouble-maker.
However, historical documents, myths, and legends about him show us that his negative image was just due to misunderstandings in the process of transmission. In fact, he was a man of worship who was expected to be able to come true Cheju pople's dearest wish. But we know he unluckily failed to do this in the end.