King Jean, known as Jean le bon (John the good), devoted his regime to the improvement and consolidation of the French government as well as reform and modernization of the army. All of these endeavors were blocked by an aristocracy protecting its own vested interests.

The year 1355 witnessed the resumption of the formal fighting between the armies of France and England, adding to the "freebooters" operating in many areas of France. In September 1356 the armies met at Poitiers in South-Central France. The English army was commanded by Edward, the Prince of Wales and the French Army by Jean II.

While Jean fought valiantly along with his teenage son Phillip, the future Duke of Burgundy, his fierce battle axe was not enough. the English won the battle, captured King Jean and took him to England.

Jean's ransom was set at 3,000,000 Ecu's (French gold crowns). Impoverished France could not come up with such a huge amount. Eventually Jean was released to return to France in order to assemble the balance of the ransom. His son Louis stood in his stead as prisoner of the English. While his father attempted to acquire the ransom, Prince Louis escaped from his captors.

King Jean, as an exceptionally proud and honorable man, returned to England as a captive. He subsequently died in captivity in 1364 and was succeeded on the throne of France by his son Charles V.