This episode details the Battle of Tinchebray in 1106, where King Henry I defeated his brother Duke Robert Curthose to secure Normandy. The narrative covers Henry’s political maneuvering, including resolving conflicts with Archbishop Anselm and navigating complex alliances amidst terrible weather. The climax features Henry’s tactical victory, achieved by dismounting knights and using a hidden reserve to flank Robert’s forces, resulting in Robert’s capture and imprisonment.