Alexios III Angelos vs King Yeonsangun of Joseon

Alexios III Angelos overthrew his brother Isaac II in a palace coup, blinding and imprisoning him. Alexios III then ruled as emperor, but his reign was marked by corruption, fiscal mismanagement, and the weakening of Byzantine defenses.

When the Fourth Crusade besieged Constantinople in 1203, Alexios III fled the city with the imperial treasury, abandoning his subjects. His cowardly flight left the capital defenseless and allowed the crusaders to restore Isaac II and Alexios IV, but also set the stage for the eventual sack of Constantinople in 1204.

Alexios III was captured by Theodore I Laskaris, the Nicaean emperor, after attempting to regain power with Seljuk support. He was imprisoned in a monastery in Nicaea, where he died later that year, ending his attempts to reclaim the Byzantine throne.

Yeonsangun ordered the execution and exile of many scholar-officials from the Sarim faction, accusing them of criticizing his rule. This purge intensified factional conflict and established his reputation for tyranny.

Yeonsangun launched a second, more brutal purge, executing hundreds of officials and their families. He targeted those involved in his mother's death and anyone who opposed his excesses, further destabilizing the court.

Yeonsangun abolished the Office of Special Counselors (Hongmungwan) and other advisory bodies, centralizing power in his own hands. This act removed checks on royal authority and allowed his tyranny to go unchecked.

A group of officials and military leaders staged a coup, deposing Yeonsangun and exiling him to Ganghwa Island. He was the first Joseon king to be forcibly removed from power, and his half-brother Jungjong was installed as king.