After the Battle of Poitiers, France's fortunes were at their lowest. In the 1360s, the new French king, Charles the Wise, led a remarkable recovery in political, financial and military strength. An English intervention in Spain then offered an opportunity to renew the Hundred Years' War. The French king and his Constable, the Breton knight Bertrand du Guesclin, carried out a spectacular reconquest that reduced English possessions in France to a remnant of Aquitaine.