Battle of Coutras The Battle of Coutras , fought on 20 October 1587 , was a major engagement in the French Religious Wars between a Huguenot ( Protestant ) army under Henry of Navarre ( the future Henry IV of France ) and a royalist army led by Anne , Duke of Joyeuse . Henry of Navarre was victorious , Joyeuse was killed while attempting to surrender . Context . The Wars of Religion between the Catholics and Protestants in France had begun in 1562 and continued intermittently since , with temporary periods of nominal peace that were often also violent . The King of France Henry III conducted a conciliatory policy , as reflected in the enactment of the Edict of Beaulieu in 1576 and the Edict of Poitiers the following year . But a new crisis arose as the result of the death of the king ' s brother , Francis of Alençon , when the Huguenot , Henry of Navarre , became heir presumptive to the throne . The League , led by the Duke of Guise , then set the kingdom against the king , who became isolated . On 18 July 1585 , Henry III promulgated an edict canceling all previous edicts , giving precedence " to the Catholics " , paying the mercenaries of the League of the Royal Treasury , prohibiting Protestantism in France , and ordering the return of safe Protestant stronghold s . Protestants were expelled from power . And while the Guise party won appointments and favours , the king of Navarre was deprived of his functions . This edict was effectively a declaration of war against the Protestants . Henry of Navarre sought support , initially without success . The " private bull " ( " bulle privatoire " ) by Pope Sixtus V brought him a measure of support from French royalists and Gallican circles ; joined by the " Politiques français " , supporters of religious tolerance ( such as the Governor of Languedoc , Montmorency - Damville ) and later England and Denmark , but only after the assassination of William of Orange , the deposition of the Elector of Cologne ( the bishop became Calvinist ) , and the success of Spain in its fight against the Protestants of the Netherlands . Faced with the intransigence of Guise , war was inevitable . Joyeuse was sent south with an army , while Mercoeur invaded Poitou and blocked Condé at La Rochelle . Battle . The clash of the two cavalry forces was to the advantage of the King of Navarre . In fact , the Duke of Joyeuse launched a charge at full gallop . By the time they came into contact , his horses were exhausted , and his squadrons of lancers lost cohesion , rendering them ineffective . For his part , Henry of Navarre adopted an innovative tactic in the disposition of his troops : he inserted the platoons of musketeer s ( five men abreast ) within cavalry squadrons , to improve their support . The charge of light cavalry Protestants broke the Royalist army , which was routed . The Duke of Joyeuse was defeated , captured and killed by a pistol shot . 2000 Catholics were also captured along with Anne ' s younger brother , Claude Joyeuse ( 1569 - 1587 ) , lord of Saint - Sauveur and Jacques d ' Amboise , the eldest of the branch of Amboise - d ' Aubijoux . Victory went to the Protestants , led by Henry of Navarre . He recovered the body of Joyeuse and attended a mass in honour of his slain enemies .