FORBES, John, British soldier, born in Petincrief, Fifeshire, Scotland, in 1710; died in Philadelphia, Pennsylvania, 11 March 1759. He became a physician, but abandoned his profession to enter the army, and was made lieutenant colonel of the Scotch Greys in 1745. In the German war he was on the staff of Lord Stair, General Ligonier, and General Campbell, was made colonel of the 17th foot, 25 February 1757, and acted as quartermaster general under the Duke of Cumberland. He was appointed brigadier general in America, 28 December 1757, and was adjutant general in the expedition against Louisburg. In the autumn of 1758 he was placed in command of the expedition against Fort Duquesne, numbering 1,200 highlanders, 350 royal Americans, and about 5,000 provincials, including about 1,000 Virginians under the command of Washington. When Forbes arrived at Raystown, Pennsylvania, with his army, in September 1758, he was carried in a litter, as he was already prostrated by the illness that shortly afterward caused his death, but his head was clear and his will firm, and he retained command of the expedition.

After Bouquet's disastrous reconnaissance (see BOUQVET, HENRY) the army reached Loyalhanna on 5 November and it was decided to pass the winter there, when news of the weakness of the fort induced Forbes to push forward. Passing the field where the bones of Braddock's men lay unburied, the expedition finally reached Fort, Duquesne on 25 November The work had been blown up and abandoned by the French on the previous day, and Washington's men marched in and took possession. Forbes renamed the place Fort Pitt (now Pittsburgh), in honor of William Pitt, who had planned the campaign, and, after concluding treaties with the Indian tribes on the Ohio, returned to Philadelphia, where he died shortly afterward. He was noted in the army for his obstinacy, and was nicknamed "The Head of Iron."