The Battle of Malplaquet, was a main battle of the War of the Spanish Succession, between the Bourbons of France and Spain against an alliance including the Habsburg Monarchy, Great Britain, the United Provinces and the Kingdom of Prussia. Unable to bring the French army under Marshal Villars to battle owing to strong French defensive lines and the Marshal's orders from Versailles not to risk battle, the Duke of Marlborough concentrated instead on taking the fortresses of Tournai and Ypres. Tournai fell after an unusually long siege of almost 70 days, by which time it was early September, and rather than run the risk of disease spreading in his army in the poorly draining land around Ypres, Marlborough instead moved eastwards towards the lesser fortress of Mons, hoping by taking it to outflank the French defensive lines in the west. Villars moved after him, under new orders from Louis XIV to prevent the fall of Mons at all costs – effectively an order for the aggressive Marshal to give battle.

After several complicated manoeuvres, the two armies faced each other across the gap of Malplaquet, south-west of Mons. Led by Marlborough and Prince Eugene of Savoy, the allied army, mainly consisted of Dutch and Austrian troops, but also with considerable British and Prussian contingents, while the French and a contingent of Bavarians were commanded by Villars and Marshal Boufflers. Boufflers was officially Villars' superior but voluntarily serving under him. The allies had about 86,000 troops and 100 guns and the French had about 75,000 and 80 guns, and they were encamped within cannon range of each other near what is now the France/Belgium border.

At 9.00am on 11 September, the Austrians attacked with the support of Prussian and Danish troops under the command of Count Albrecht Konrad Finck von Finckenstein, pushing the French left wing back into the forest behind them. The Dutch under command of John William Friso, Prince of Orange, on the Allied left wing, attacked the French right flank half an hour later, and succeeded with heavy casualties in distracting Boufflers enough so that he could not come to Villars' aid. Villars was able to regroup his forces, but Marlborough and Eugène attacked again, assisted by the advance of a detachment under General Withers advancing on the French left flank, forcing Villars to divert forces from his centre to confront them. At around 1.00 pm Villars was badly wounded by a musket ball which smashed his knee, and command passed to Boufflers. The decisive final attack was made on the now weakened French centre by British infantry under the command of the Earl of Orkney, which managed to occupy the French line of redans. This enabled the Allied cavalry to advance through this line and confront the French cavalry behind it. A fierce cavalry battle now ensued, in which Boufflers personally led the elite troops of the Maison du Roi. He managed no less than six times to drive the Allied cavalry back upon the redans, but every time the French cavalry in its turn was driven back by British infantry fire. Finally, by 3.00 pm Boufflers, realising that the battle could not be won, ordered a retreat, which was made in good order. The Allies had suffered so many casualties in their attack that they could not pursue him. By this time they had lost over 21,000 men, almost twice as many as the French. By the norms of warfare of the era, the battle was an allied victory, because the French withdrew at the end of the day's fighting, and left Marlborough's army in possession of the battlefield, but with double the casualties. In contrast with the Duke's previous victories, however, the French army was able to withdraw in good order and relatively intact, and remained a potent threat to further allied operations.