The Treaty of Brétigny had made Edward III renounce his claim to the French crown. At the same time it greatly expanded his territory in Aquitaine and confirmed his conquest of Calais. In reality, Edward never renounced his claim to the French crown, and Charles made a point of retaking Edward's new territory as soon as he ascended to the throne. In 1369, on the pretext that Edward III had failed to observe the terms of the treaty of Brétigny, Charles declared war once again.
The reign of Charles V saw the English steadily pushed back.
The Black Prince was occupied with war in Iberian peninsula from 1366 and due to illness was relieved of command in 1371, whilst Edward III was too elderly to fight; providing France with even more advantages. Pedro of Castile, whose daughters Constance and Isabella were married to the Black Prince's brothers John of Gaunt and Edmund of Langley, was deposed by Henry of Trastámara in 1370 with the support of Du Guesclin and the French. War erupted between Castile and France on one side and Portugal and England on the other.
With the death of John Chandos, seneschal of Poitou, in the field and the capture of the Captal de Buch, the English were deprived of some of their best generals in France. Du Guesclin, in a series of careful Fabian campaigns, avoiding major English field armies, captured many towns, including Poitiers in 1372 and Bergerac in 1377. The English response to Du Guesclin was to launch a series of destructive chevauchées. But Du Guesclin refused to be drawn in by them.
With the death of the Black Prince in 1376 and Edward III in 1377, the prince's underaged son Richard of Bordeaux succeeded to the English throne. Then, with Du Guesclin's death in 1380, and the continued threat to England's northern borders from Scotland represented by the Battle of Otterburn, the war inevitably wound down to a truce in 1389. The peace was extended many times before open war flared up again.