Taejo of Joseon was the founder and the first king of the Joseon dynasty of Korea. After ascension to the throne, he changed his name to 李旦 . He reigned from 1392 to 1398, and was the main figure in the overthrowing of the Goryeo Dynasty.

An early achievement of the new monarch was improved relations with Ming China; this had its origin in General Yi's refusal to attack their neighbour in response to raids from Chinese bandits. Shortly after his accession, the king sent envoys to inform the Ming court at Nanjing that a dynastic change had taken place. Korean envoys were dispatched to Japan, seeking the re-establishment of amicable relations. The mission was successful, and Shōgun Ashikaga Yoshimitsu was reported to have been favorably impressed by this initial embassy. Envoys from the Ryūkyū Kingdom were received in 1392, 1394 and 1397. Siam sent an envoy in 1393.

Taejo abdicated in 1398 during a strife between his sons and died in 1408.