Goryeo
Taejo made important policies. First, he insisted that Goryeo should expand its territory to further North. It is because he succeed to Goguryeo (ancient Korean kingdom founded in 37 BC–668) and Goguryeo had the biggest territory in Korean history. So, Taejo named the dynasty as Goryeo from Goguryeo and tried to take back the territory of Goguryeo. He emphasized the importance of Sukyung area because it is placed in the North part and kept in check Gu Ran (kind of Mongolian) that made an effort to come down to Goryeo. Later, all of these policies contributed to expanding its territory to Apnok River. Taejo unified all people from different Korean kingdoms (Baekje, Silla, Goguryeo, Balhae). Because of this policy, Goryeo is considered to have united Korea.