Alexios I Komnenos vs Yi Seong-gye

Alexios I Komnenos was defeated by the Norman army under Robert Guiscard at Dyrrhachium. The Byzantine forces were routed, and Alexios barely escaped. This loss allowed the Normans to occupy much of the western Balkans, though Alexios later recovered some territory.

Alexios I implemented a series of reforms to restore Byzantine power. He reorganized the army by relying more on foreign mercenaries, reformed the currency (the hyperpyron), and granted tax exemptions to the Church. These measures stabilized the empire after decades of decline.

Alexios I sent envoys to Pope Urban II at the Council of Piacenza, requesting military aid against the Seljuk Turks. This appeal contributed to Urban's call for the First Crusade at the Council of Clermont later that year, initiating the Crusader movement.

Alexios I cooperated with the Crusader army to besiege and capture Nicaea from the Seljuk Turks. The city was surrendered to Byzantine control, and Alexios used the Crusaders to recover key territories in Anatolia, though tensions later arose over land claims.

Yi Seong-gye led Goryeo forces against Japanese pirates (wokou) at the Battle of Hwangsan. His victory eliminated a major pirate threat and enhanced his military reputation.

Yi Seong-gye turned his army back at Wihwado Island rather than invade Ming China as ordered by the Goryeo court. This act of defiance led to a coup that eventually brought him to power.

Yi Seong-gye overthrew the Goryeo dynasty and founded the Joseon dynasty, becoming King Taejo. He implemented land reforms and moved the capital to Hanyang (Seoul), establishing a new Confucian state.