Around the same time, Balhae collapsed and its last crown prince fled south to Goryeo.
Goryeo (also spelled as Koryŏ), whose name developed into the modern exonym "Korea", was a highly cultured state that created the world's first metal movable type in 1234.
It is separated from Japan to the east by the Korea Strait and the Sea of Japan (East Sea).
Korea emerged as a singular political entity in 676CE after centuries of conflict among the Three Kingdoms of Korea, which were unified as Unified Silla to the south and Balhae to the north.
To date, each country contends that it is the sole legitimate government of all of Korea; they refuse to recognize the other as legitimate.