Urgent need to expand Britain’s puny aircraft industry at start of First World War led to George Holt Thomas of Airco asking advice on capable woodworking firms from his chief supplier of spruce and ash, William Mallinson & Son. One company recommended was H.H. Martyn, at Sunningend Works, Cheltenham. Hugh Burroughes was sent to evaluate them in April 1915 and was impressed. Soon Martyn was deluged with work on Nieuport scouts and Bristol Fighters, and on major parts for many other aircraft. In 1917 Airco and Martyn discussed forming 50/50-owned company to rent expanding Sunningend factory and take over Airco’s large subcontract business. As result Gloucestershire Aircraft Co. was registered 5 June 1917, and GAC soon became major unit in now large industry, drawing employees from throughout Gloucester/Cheltenham area. By 1918 it was producing 45 FE.2b, Fighter and Nighthawk aircraft per week, each towed 7 miles to Air Board acceptance park at Hucclecote, on other side of Gloucester. All contracts slashed at Armistice. Holt Thomas sold Airco, and many other firms shut down, including British Nieuport. Post-war contractual settlement imposed on GAC required firm to accept large quantities of Nieuport parts, especially for Nighthawk fighters. Nieuport’s designer, Harry Folland, agreed to help GAC improve Nighthawk and modify these parts, and soon Gloucestershire aircraft were flying at remarkable speeds with Jaguar, Jupiter and Lion engines. One group, called Bamels (Bear/Camel), were racers, leading to Schneider Trophy contenders, while others, called Sparrowhawks, were important in setting up air arm of Japanese navy from 1921. In that year Folland was formally appointed chief engineer, starting 14-year period in which his radial-engined biplane fighters achieved great success, best-known types being Grebe, Gamecock, Gauntlet and Gladiator. But in May 1934 Hawker made takeover proposal which GAC-which from 1926 had spelt its name Gloster to help export customers-accepted, starting Hawker Siddeley Group. Folland left to set up his own firm, and successor W.G. Carter at once created excellent stressed-skin monoplanes but failed to win orders, firm being sustained by making Hawker aircraft: Hardy, Hart, Audax, all 200 Henleys, 2,750 Hurricanes and all 3,313 Typhoons. Carter did, however, win contracts for Britain's first jets, 2 E.28/39 testbeds being followed by F.9/40 Meteor. Wartime expansion saw GAC with giant plants all round Gloucester. One was assembly building of fictitious firm A.W. Hawksley, set up to produce 600 AW.41 Albemarles. From 1943 GAC built 2,974 Meteors of 10 marks, night fighters being assigned to sister firm Armstrong Whitworth. Last GAC aircraft was massive Javelin night fighter, of which 302 were made by GAC and 133 by Armstrong Whitworth, the 2 firms becoming Hawker Siddeley’s Whitworth Gloster division in October 1961.