Taejo of Joseon

General Yi Seong-gye defeated a Japanese pirate (wokou) force at Hwangsan. This victory enhanced his military reputation and demonstrated his capability as a commander.

General Yi Seong-gye, ordered to invade the Ming dynasty's Liaodong region, turned his army back at Wihwado Island. This act of defiance against the Goryeo court led to a coup that eventually brought him to power.

Taejo implemented the Gwajeon Law, a land reform that redistributed land from the old Goryeo aristocracy to his supporters and the state. This weakened the old elite and strengthened the new Joseon ruling class.

Yi Seong-gye deposed the last Goryeo king and founded the Joseon dynasty, with its capital at Hanyang (modern Seoul). He established a new ruling class based on Confucian ideology, replacing the Buddhist-influenced Goryeo system.

Taejo of Joseon ordered the compilation of the Gyeongguk Daejeon, a comprehensive legal code that established the administrative and social structure of the Joseon dynasty. This code remained in effect for centuries.