King U of Goryeo vs Louis of Nevers

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.

Louis of Nevers inherited the County of Flanders upon the death of his grandfather, Robert III. His succession was contested by his father's claims, but he secured the title through French support, aligning Flanders closely with the French crown.

Louis of Nevers, with French military aid, crushed a major peasant and urban revolt in Flanders led by Nicolaas Zannekin. The revolt was sparked by his pro-French policies and tax burdens, and its suppression solidified his rule but alienated many Flemings.

Louis of Nevers, Count of Flanders, fought on the French side against the English army of Edward III. He was killed during the battle, which ended in a decisive English victory and marked the beginning of the Hundred Years' War's first phase.