The Battle of Malplaquet was a battle of the War of the Spanish Succession that took place on September 11, 1709 between France and a British–Austrian alliance (known as the Allies).

The British and Austrians were led by the Duke of Marlborough and Prince Eugène of Savoy, with a contingent of Dutch troops, while the French were commanded by Marshal Villars and Marshal Boufflers. Each side had about 90,000 troops, and were encamped within cannon range of each other near the Belgian border. The Austrians attacked at 9 am, pushing the French back into the forest behind them. The Dutch broke off to attack the French right flank and were defeated with heavy casualties, but they distracted Boufflers enough that he could not come to Villars aid.

Villars was able to regroup his forces, but Marlborough and Eugène attacked again and forced Villars to retreat by 3 pm. The Allies had suffered so many casualties in their attack that they could not pursue him; by this time they had lost 20,000 men, twice as many as the French. It was the bloodiest battle of the war, and prevented the Allies from moving on towards Paris.