The Battle of Bouvines, July 27, 1214, was the first great international conflict of alliances among national forces in Europe. In the alliances, which were orchestrated by Pope Innocent III, Philip Augustus of France defeated Otto IV of Germany and count Ferrand of Flanders so decisively that Otto was deposed and replaced by Frederick II Hohenstaufen. Ferrand was captured and imprisoned. Philip was himself able to take undisputed control of the territories of Anjou, Brittany, Maine, Normandy, and the Touraine, which he had recently seized from Otto's kinsman and ally John of England.
The city of Bouvines is between Lille and Tournai, and in the 13th century was in the County of Flanders and is part of modern France.
The campaign plan seems to have been designed by John, who was the fulcrum of the alliances; his general idea was to draw the French king away from Paris southward against himself and keep him occupied, while the main army, under emperor Otto IV, with the counts of the low countries, should march on Paris from the north. John's part in the general strategy was carried out at first, but the allies in the north moved slowly. John, after two encounters with his mortal enemy of France, turned back to his Guienne possessions on July 3, however, perhaps in one of his fits of despondency. When, three weeks later, the emperor finally concentrated his forces at Valenciennes, John was out of the picture, and in the interval Philip Augustus had countermarched northward and regrouped. Philip now took the offensive himself, and in maneuvering to get a good cavalry ground upon which to fight he offered battle (July 27), on the plain east of Bouvines and the river Marque. The imperial army drew up facing south-westward towards Bouvines, the heavy cavalry in the new-fangled plate armour on the wings, the infantry in one great mass in the center, supported by the cavalry corps under the emperor himself. The total force is estimated at 6500 heavy cavalry and 40,000 foot solidiers. The French army (about 7000 cavalry and 30,000 infantry) took ground exactly opposite in a similar formation, cavalry on the wings, infantry, including the townsmen (milice des communes) in the center, Philip with the cavalry reserve and the royal standard, the Oriflamme , in rear of the men on foot.
The battle opened with a confused cavalry fight on the French right, in which individual feats of knightly gallantry were more noticeable (and better recorded in the chronicles) than any attempt at combined action. The serious fighting was between the two centers; the infantry of the Low Countries, who were at this time almost the best in existence, drove back the French. Philip led the cavalry reserve of nobles and knights to retrieve the day, and after a long and doubtful fight, in which he himself was unhorsed and narrowly escaped death, began to drive back the Flemings. In the meanwhile the French feudatories on the left wing had thoroughly defeated the imperial forces opposed to them, and William Longsword, Earl of Salisbury, the leader of this corps, was unhorsed and taken prisoner by the fighting bishop of Beauvais. On the other wing the French at last routed the Flemish cavalry and captured Ferdinand Count of Flanders, one of the leaders of the coalition. In the center the battle was now a melée between the two mounted reserves led by the king and the emperor in person. Here too the imperial forces suffered defeat, Otto himself being saved only by the devotion of a handful of Saxon knights. The day was already decided in favor of the French when their wings began to close inwards to cut off the retreat of the imperial center. The battle closed with the celebrated stand of Reginald of Boulogne, a former vassal of King Philip, who formed a ring of seven hundred Brabancon pikemen, and not only defied every attack of the French cavalry, but himself made repeated charges or sorties with his small force of knights. Eventually, and long after the imperial army had begun its retreat, the gallant schiltron was ridden down and annihilated by a charge of three thousand men-at-arms. Reginald was taken prisoner in the mele; and the prisoners also included two other counts, Ferdinand and William Longsword, twenty-five barons and over a hundred knights. The killed amounted to about 170 knights of the defeated party, and many thousands of foot on either side.
John returned to England to face the barons whose possessions in Normandy he had lost. After Bouvines there were no important wars in Western Europe until the 1290s.
Georges Duby, The Legend of Bouvines (1990). A careful study of the historiography of a single event, Duby examines how the Battle of Bouvines has been used and abused in French history.