Leigh-Mallory was a controversial figure but a very successful fighter commander. At the outbreak of the war Leigh-Mallory was in command of No 12 (Fighter) Group which was responsible for the defense of the Midlands and the east coast shipping routes. He favored the use of ‘big wing’ formations in the Battle of Britain, which meant that a massive concentration of intercepting forces had to be available inland. The Commander in Chief of Fighter Command (DOWDING) and the Commander of No 11 Group in the south of England were against this and there were bitter disputes. In December 1940 Leigh-Mallory became Commander of No 11 Group and with DOUGLAS as Head of Fighter Command was able to shift Fighter Command onto the offensive. In November 1942 Leigh- Mallory was appointed Head of Fighter Command and in 1943 Commander in Chief of the Allied Air Forces for the coming invasion of Europe. Again he became involved in a dispute because he wanted control of the British and US strategic bomber forces, but their Commanders HARRIS and SPAATZ insisted on their operating independently. Leigh-Mallory’s greatest contribution to Operation Overlord was his Transportation Plan, which advocated a concentrated bombing of German communications prior to the landings.
On the whole he was successful in this role and the 9000 aircraft under his command denied free use of the air to the Luftwaffe. In November 1944 Leigh-Mallory was appointed Commander in Chief of South East Asia Command but he was killed with his wife in an air crash while en route.