The Battle of Pontvallain, part of the Hundred Years' War, took place in the Sarthe region of north-west France on 4 December 1370, when a French army under Bertrand du Guesclin heavily defeated an English force which had broken away from an army commanded by Sir Robert Knolles. The French numbered 5,200 men, and the English force was approximately the same size.
The English had plundered and burnt their way across northern France from Calais to Paris. With winter coming, the English commanders fell out and divided their army into four. The battle consisted of two separate engagements: one at Pontvallain where, after a forced march, which continued overnight, Guesclin, the newly appointed constable of France, surprised a major part of the English force, and wiped it out. In a coordinated attack, Guesclin's subordinate, Louis de Sancerre, caught a smaller English force the same day, at the nearby town of Vaas, also wiping it out. The two are sometimes named as separate battles.