Quatre Bras, Battle of, June 16, 1815, a battle between French and British forces two days before Napoleon's defeat at Waterloo. Quatre Bras is a Belgian village near Brussels. Marshal Ney of France, commanding 48,000 troops, was ordered to take Quatre Bras. Ney, mismanaging his forces, was delayed in taking his objective and was not able to assist Napoleon in an attack on the Prussian army at Ligny. Because Ney was not there on time, the Prussians, although defeated, managed to withdraw their army. This failure on the part of Ney set the stage for Napoleon's defeat two days later.