he recurring challenge that weighed on pre-modern Korea, no matter its leadership, was establishing harmony between China and Japan. The Goryeo dynasty (918 – 1392) stayed independent through peace with the Yuan dynasty but was under threat from the Ming dynasty by the late 1300s. In a bid to quell domestic unrest and normalise ties with the Chinese, a Goryeo general named Yi Seong-gye overthrew his monarch. Yi began his reign
