Battle of the Monongahela, (July 9, 1755), in the last French and Indian War, thorough defeat of General Edward Braddockâs British army by a smaller force of French and Indians of several tribes led by Captain Daniel de Beaujeu and, after his death, by Captain Jean Dumas. After a slow march from Fort Cumberland in northwest Maryland toward Fort Duquesne (modern Pittsburgh), Pa., the British party met the French and their Indian allies, whose style of fighting won the battle and kept Fort Duquesne in French possession. Unused to fighting except in formations appropriate to European warfare, the British regulars were routed. Of the 1,459 British troops actively engaged, almost 1,000 were killed or wounded. The survivors included George Washington, then a civilian aide-de-camp to Braddock. When Braddock died from battle wounds on July 13, Colonel Thomas Dunbar assumed command of the British remnant and withdrew to Fort Cumberland.