Baldwin IV of Jerusalem vs King U of Goryeo

Baldwin IV, despite suffering from leprosy, led a small force to victory against Saladin's larger army at Montgisard. Saladin was forced to retreat to Egypt, and the victory boosted Christian morale in the Kingdom of Jerusalem.

Baldwin IV led a relief force to the Siege of Kerak, where Saladin was besieging the castle. Baldwin's arrival forced Saladin to lift the siege, demonstrating Baldwin's continued military leadership despite his illness.

Due to his worsening leprosy, Baldwin appointed Guy of Lusignan as regent. This decision proved disastrous, as Guy's incompetence led to internal strife and ultimately the loss of Jerusalem.

Baldwin IV had his nephew, Baldwin V, crowned co-king to ensure a smooth succession and prevent Guy of Lusignan from inheriting the throne. This move aimed to stabilize the kingdom but failed after Baldwin IV's death.

King U became king at age 9 after the death of King Gongmin, with support from the Yuan court. His youth and alleged illegitimate birth (rumored to be the son of a Buddhist monk) made his rule controversial from the start.

King U was deposed by General Yi Seong-gye (later King Taejo of Joseon) after Yi's coup. Yi accused U of being unfit to rule and of plotting against the state, and placed U's son King Chang on the throne as a puppet.

King U was executed along with his son King Chang by Yi Seong-gye's forces, after Yi decided to eliminate all potential rivals. This brutal act cleared the way for Yi to establish the Joseon dynasty in 1392.