Goryeo

Goryeo was the dynasty that unified the Korean peninsula under the Wang house and ruled it for nearly five centuries. Its founder Wang Geon, a general of the warlord Gung Ye, seized power in 918, made his capital at Kaesong, received the submission of Silla in 935 and destroyed Later Baekje in 936, closing the Later Three Kingdoms period. The new state kept Silla's bone-rank aristocracy but checked it with Chinese-style institutions: Seongjong reorganised the provinces, and from 958 the civil examinations recruited officials by learning rather than birth. Goryeo beat back three Khitan invasions, the last shattered by Gang Gam-chan at Guiju in 1018, and walled its northern frontier. Buddhism was the state religion, and its monasteries produced the refined celadon, the Tripitaka Koreana carved in eighty thousand woodblocks during the thirteenth-century Mongol invasions, and the world's oldest surviving movable metal type. Those invasions, beginning in 1231, forced the court onto Ganghwa Island for decades and ended in a humiliating vassalage sealed by Mongol princess brides. The dynasty recovered some ground under Gongmin, but land hunger, Red Turban raids and factional generals hollowed it out. In 1388 the general Yi Seong-gye turned his army back from the frontier, and in 1392 he took the throne and founded Joseon.