During the last period of Shilla, the powereful clans were much stronger than the nobles. They had their own territories, but the central government didn't. While the Shilla nobles were losing control of their power, the familes raised a large number of forces.

 Gyeon-hwon first estabilshed a later Baekje, and Gung-ye established a later Goguyeo. They were both from Shilla, but had different reasons for establishing their own countries. Gyeon-hwon was a son of a peasant, and it was very hard to eat and live for their family. So he became a solider, but he did not get much more advantage. From that day, he thought about building a better country where people could live happily without fear. Gung-ye was a prince of Shilla, but was thrown out because it was said he was unlucky and would kill his father for the throne. In the process of getting thrown out, he injured his left eye and could not ever see with it ever again. When he grew up, he found out about his story, he wanted revenge. As a result, Gung-ye established the later Goguyeo. When there was Shilla, a later Baekje, a later Goguyeo, we call this the later Three Kindoms.

At this time, Wang-geon, later the establisher of Goyeo, was one of the best-trusted followers of Gung-ye. However, Gung-ye became greedier, and started to get mad and think he is a god. Later, people didn't like Gung-ye anyomore and pursuaded Wang-geon to take the throne. So he got rid of Gung-ye and established Goryeo in 918AD.