Goryeo
Goryeo (고려) was a Korean state founded in 918, during a time of national division called the Later Three Kingdoms period, that unified and ruled the Korean Peninsula until the establishment of Joseon in 1392.
Goryeo achieved what has been called a "true national unification" by Korean historians. According to these historians, it was during the Goryeo period that the individual identities of Goguryeo, Baekje and Silla were successfully merged into a single entity that became the basis of the modern-day Korean identity. The name "Korea" is derived from the name of Goryeo.
Commerce, art, and culture flourished in Goryeo.
Goryeo, alongside the preceding Unified Silla, was known to be the "Golden Age of Buddhism" in Korea. As the state religion, Buddhism achieved its highest level of influence in Korean history, with 70 temples in the capital alone in the 11th century.
When Goryeo was succeeded by Joseon in 1392, state support switched to Confucianism, and Buddhism was discouraged.
Further reading
Joseon, Wikipedia
