Wihwado Retreat
When the Ming claimed the land north of Cheollyeong, King U and Choe Yeong launched an expedition against Liaodong, but Yi Seong-gye turned the army back at Wihwado, ousted Choe Yeong and seized power.
The Ming announced it would set up the Tieling Commandery to claim the land north of Cheollyeong once held by the Yuan. King U and Choe Yeong resolved to attack Liaodong. Yi Seong-gye objected with his "four reasons against": a small country should not defy a large one, troops should not be raised in summer, a distant campaign would leave the country open to pirates, and the monsoon would loosen the glue of the bows and spread disease.
Reaching Wihwado in the Yalu, Yi Seong-gye and Jo Min-su turned back in the fifth month of 1388, entered Gaegyeong, exiled (and later executed) Choe Yeong, deposed King U and enthroned King Chang. Power passed to Yi Seong-gye and the new scholar-officials, opening the way to the founding of Joseon.
