Taejo of Joseon (4 November 1335 – 27 June 1408), born Yi Seong-gye (Hangul: 이성계, Hanja: 李成桂), was the founder and first ruler of the Joseon Dynasty of Korea. After ascending to the throne, he changed his name to Yi Dan (Hangul: 이단, Hanja: 李旦). He reigned from 1392 to 1398, and was the main figure in the overthrowing of the Goryeo Dynasty. Taejo joined the Goryeo army and rose through the ranks before finally seizing the throne in 1392. He abdicated in 1398 during a strife between his sons and died in 1408.