As the Ottoman Turks under Sultan Bajazet I advanced through the Balkans, King Sigismund of Hungary appealed to Western Europe for a crusade. The duke of Burgundy sponsored the expedition, placing his 24-year-old son, Jean de Nevers, in nominal command. Enguerrand de Coucy was asked by Burgundy to serve as chief counselor, though in the final arrangement he appeared on a separate advisory list to be consulted “when it seemed good” to Nevers rather than as a formally designated primary counselor (548). The French-led army, resplendent in magnificent armor and livery, traveled down the Danube River, but their arrogance, debauchery, and pillaging alienated their local allies.

At a war council in Buda, the French leadership rejected Sigismund’s prudent advice for a defensive strategy, insisting on aggressively seeking out the enemy. After capturing the fortresses of Vidin and Rachowa, the crusaders violated the terms of the latter’s surrender by massacring their Turkish prisoners, an act that angered Sigismund and would later prove fatal. On September 25, 1396, as the armies prepared for battle at Nicopolis, the French again ignored Sigismund’s tactical plan. Led by the reckless Constable d’Eu, who demanded the place of honor in the vanguard, the French knights charged ahead of the main army. Though they initially overwhelmed the Turkish frontline conscripts and then routed trained Turkish infantry, their undisciplined pursuit left them exhausted and disorganized when they crested the plateau, where a fresh reserve corps of sipahis held back by Bajazet destroyed them. On the plain below, Serbian cavalry under Stephen Lazarevich intervened decisively against Sigismund’s force, completing the rout. The crusade ended in a catastrophic defeat. Enraged by his losses and the massacre at Rachowa, Bajazet ordered most prisoners executed; Jacques de Helly, recognized by Turkish officials for his prior service under Murad I, was called upon to identify the leading nobles—among them Coucy, d’Eu, Boucicaut, and Nevers—who were spared for ransom, along with those judged under 20 who were to be taken away for forced service in the Ottoman Empire.

Following the disaster at Nicopolis, the captured nobles, including Enguerrand de Coucy and Jean de Nevers, were forced on a brutal 350-mile march to Gallipoli. After two months there, the prisoners were transferred to Brusa, the Ottoman capital in Asia. Trading ships brought news of the defeat to Venice on December 16, but Paris did not receive official confirmation until Christmas Day, when Jacques de Helly arrived “all booted and spurred” at the Palace of St. Pol (566), plunging the court and the country into mourning. The duke of Burgundy immediately began the difficult task of raising a ransom of 200,000 gold ducats, dispatching ambassadors with extravagant gifts intended to appease Sultan Bajazet.

In captivity at Brusa, Coucy fell ill. On February 16, 1397, “infirm of body” (570), he dictated his last will and died two days later. His heart and remains were eventually returned to France for burial. The complex process of raising the ransom was managed by the Italian banker Dino Rapondi, with important loans provided by the Knights of Rhodes and merchants in the Levant. Comte d’Eu died on June 15, nine days before the remaining prisoners were released on June 24. Henri de Bar died of plague in Venice while still awaiting return to France. In February 1398, the few surviving leaders finally returned to France. Despite the calamitous loss, they were greeted with triumphal parades and celebrations. However, contemporary moralists like Philippe de Mézières attributed the defeat to the pride, indiscipline, and vainglory of the French knights, viewing the crusade as a deep failure of the chivalric ideal.

The calamities of the 14th century extended into the 15th. In 1407, John the Fearless—Jean de Nevers, who had succeeded his father as duke of Burgundy in 1404—assassinated his rival Louis d’Orléans, plunging France into a destructive civil war between the Burgundians and the Armagnacs. Exploiting this chaos, King Henry V of England invaded and inflicted another catastrophic defeat on French chivalry at the Battle of Agincourt in 1415. The murder of John the Fearless on the bridge at Montereau in 1419 led his son Philip of Burgundy to enter into full alliance with the English, producing the 1420 Treaty of Troyes, which disinherited the dauphin Charles and named the English king heir to the French throne.

France’s fortunes were revived by the appearance of Jeanne d’Arc in 1428, whose victories led to the coronation of King Charles VII. Though she was captured and executed, her leadership marked a turning point. The Hundred Years’ War finally ended in 1453 with a French victory at Castillon, won by artillery rather than knights. The same year saw the fall of Constantinople to the Turks and the first printing from movable type by Gutenberg, signaling the close of the medieval era. Coucy’s barony was sold to Louis d’Orléans under contested circumstances—only 60,000 of the 400,000-livre price was paid down, and much of the balance was never collected—and eventually passed to the French crown when Louis d’Orléans’s grandson became Louis XII. The great castle, a symbol of feudal power, was partially dismantled in the 17th century, and its colossal keep was deliberately destroyed by the German army in 1917.