At the Battle of Brignais, the Great Mercenary Companies defeat the French Royal Army commanded by Jean de Melun, Comte de Tancarville.
Since the start of the Hundred Years' War, France has been beaten at Crécy (1346) and at Poitiers (1356), where King Jean II le Bon was taken prisoner. He was only released in 1360. During the truce, the mercenaries of the big companies, who were no longer paid, ravaged and plundered the French countryside. The king decides to destroy them. These unite to better resist.
On April 6, 1362, the Tard-Venus, a company of mercenaries formed after the Treaty of Brétigny, benefiting from the effect of surprise, cut the royal army to pieces at Brignais, south of Lyon. Several barons died there, including Jacques de Bourbon, Count of La Marche, Constable of France, and Louis d'Albon, Count of Forez. In addition, many lords were captured.
This defeat was due to the lack of discipline of the knights who, having no infantry, progressed without the essential protection of scouts and flankers (scouts placed on the flanks of an army).
The defeat caused further panic in the kingdom. However, the unit of the mercenaries did not last, and the king of France organized campaigns as far as Spain and Hungary to get rid of them.