The provision of direct air support was of central importance to the success enjoyed by Anglo-American armies during the latter half of the Second World War. This advantage, however, was the product of a long and bitter dispute between the British Army and the Royal Air Force that began at the end of the First World War and continued virtually unabated until it was resolved in late 1942 and early 1943 when the 2nd Tactical Air Force was created. This book examines the nature of this dispute. Material for the book is drawn primarily from the rich collection of documents at the National Archives and other British archives.The author makes a highly original point that Britain's independent RAF was in fact a disguised blessing for the Army and that the air force's independence was in part a key reason why a successful solution to the army's air support problems was found. The analysis traces why the British army went to war in 1939 without adequate air support and how an effective system of support was organized by the RAF.The book is divided into two equal parts of five chapters. Part one surveys how the British Army went to war in 1939 without adequate air support, and part two explains how an effective system of air support was organized by the middle years of the war. The analysis traces Britain's earliest experience with aircraft in the Great War 1914-1918, the inter-war period of doctrinal development and inter-Service rivalry, and the major campaigns in France and the Middle East during the first half of the Second World War when the weaknesses in Army-RAF co-operation were first exposed and eventually resolved. As such, it is the first scholarly survey of the origin and development of British air support doctrine and practice during the early years of the Second World War.