The attack on Fort Duquesne was part of a large-scale British expedition with 6,000 troops led by General John Forbes to drive the French out of the contested Ohio Country (the upper Ohio River Valley) and clear the way for an invasion of Canada. Forbes ordered Major James Grant of the 77th Regiment to reconnoiter the area with 850 men. Grant, apparently on his own initiative, proceeded to attack the French position using traditional European military tactics. His force was out-maneuvered, surrounded, and largely destroyed by the French and their native allies led by François-Marie Le Marchand de Lignery. Major Grant was taken prisoner and the British survivors retreated fitfully to Fort Ligonier.

After repulsing this advance party, the French, deserted by some of their native allies and vastly outnumbered by the approaching Forbes, blew up their magazines and burnt Fort Duquesne. In November the French withdrew from the Ohio Valley and British colonists erected Fort Pitt on the site.