Trafford Leigh-Mallory was born in Mobberley, Cheshire, the son of Herbert Leigh Mallory, (1856–1943), Rector of Mobberly, who legally changed his surname to Leigh-Mallory in 1914. He was the younger brother of George Mallory, the noted mountaineer.
He was educated at Haileybury and at Magdalene College, Cambridge where he was a member of a literary club and where he made the acquaintance of Arthur Tedder, the future marshal of the Royal Air Force. He passed his Bachelor of Laws degree and had applied to the Inner Temple in London to become a barrister when, in 1914, war broke out.
He remained in the Royal Air Force (RAF) in the interwar period, becoming an air vice-marshal in 1938. The previous year he had been appointed commander of the Number 12 Group in RAF Fighter Command, whose main responsibility during the Battle of Britain (June 1940–April 1941) was to defend England’s Midlands against German air attacks. A debate over tactics during the battle brought Leigh-Mallory into conflict with the Number 11 Group commander, Keith Park (in charge of defending southern England), and with the head of Fighter Command, Hugh Dowding. In defending Britain against German air attacks, these two commanders stressed the timely, well-directed use of individual fighter squadrons to intercept German planes, whereas Leigh-Mallory advocated the use of massive five-squadron formations that would achieve an overwhelming air superiority but were difficult to marshal properly.
Leigh-Mallory’s intrigues against Dowding contributed to the latter’s replacement as head of Fighter Command in November 1940, and Leigh-Mallory took over the Number 11 Fighter Group the following month. He became the head of Fighter Command in November 1942. The following year he was promoted to air chief marshal and then became commander in chief of the Allied Expeditionary Air Forces, which were to be used in the projected Allied invasion of France in the spring of 1944. Leigh-Mallory thus became the commander of some 9,000 U.S. and British aircraft allotted to this operation, and he found himself in the middle of numerous debates about how best to use aircraft to assist in the invasion. His great achievement in this role was the Transportation Plan, a massive bombing campaign against German and northern French railroads and marshaling yards prior to the invasion in order to prevent the Germans from bringing up reinforcements to attack the Allies’ beachhead in Normandy. Leigh-Mallory expressed grave doubts about the wisdom of dropping paratroops onto the Cotentin Peninsula on the eve of D-Day (June 6, 1944), but, in the campaign that followed, he cooperated with army commanders such as British Field Marshal Bernard Montgomery and U.S. General Omar Bradley in directing the carpet bombing of German defenses in advance of Allied armoured assaults.
Leigh-Mallory was appointed head of Allied air forces in Southeast Asia in November 1944 but was killed in a plane crash en route to his new command. He had been knighted in 1943.
Leigh-Mallory was a keen sailor.
After one of his children survived a serious illness, Leigh-Mallory became interested in faith healing and spiritualism. In one anecdote, he suggested he had seen the ghost of Emily Langton Massingberd, the women's rights campaigner, at Gunby Hall in Lincolnshire. When the building was threatened with demolition during the Second World War to make way for an airfield, Leigh-Mallory intervened to save it. It is now in the hands of the National Trust.
Trafford married Doris Sawyer in 1915, the couple had two children.
