On April 6, 1362, at the Battle of Brignais near Lyon, the Free Companies—groups of mercenaries left unemployed by the Treaty of Brétigny—defeated the French royal army led by James I of Bourbon. This shocking victory demonstrated the military effectiveness of these freelance soldiers and highlighted the fragility of royal authority in post-war France. The battle forced the French crown to negotiate with the mercenaries, ultimately diverting them to campaigns in Spain and Italy.

The Battle of Brignais and the phenomenon of the Free Companies captured the imagination of chroniclers and poets who wrote about the chaos and moral ambiguity of mercenary warfare. The figure of the routier—the displaced soldier turned bandit—became a stock character in French and English literature, representing both the violence of the age and the social dislocation caused by prolonged conflict. This literary archetype would persist for centuries, appearing in the works of Shakespeare and later in the romanticized portrayals of mercenaries in 19th-century poetry.