The Battle of Amiens was one of the most influential battles of the twentieth century. Four days of intense combat from 8–12 August 1918 saw the British Fourth and French First Armies shatter the German Second Army and drive it back, together with the German Eighteenth Army, up to 20 km on a 50 km front between the Oise and the Ancre. In the process the British and French took 30,000 prisoners of war, killed or wounded at least another 13,000 men, and captured almost 500 guns. Although more widely associated with the massed use of tanks, the Battle of Amiens also saw the largest concentration of British airpower for a single operation in the war. Deployed as a separate service for the first time in a major offensive, the Royal Air Force (RAF) played a pivotal role in the combat performance of the Fourth Army. Swarming over the battlefield, its aircraft engaged any German defenders in direct contact with the leading ground troops, harried the retreat of those less resolute and repeatedly drove reinforcements from the road as they struggled forwards in an attempt to avert disaster. In the course of the battle, both the Army and the RAF identified many lessons which they ruthlessly applied during the remainder of the war. As a result they developed a potent Air-Land capability which struck with repeated success at the German Armies in the west and ultimately drove them to request an Armistice.
However, the events at Amiens also provided a critical point of reference that directly influenced the development of British Air-Land battle in the interwar period and its subsequent conduct in the Second World War. In its efforts to maintain its existence as an independent Service in a period of severe economic retrenchment, the RAF used its experiences at Amiens to distance itself from the task of close air support before recasting the role of airpower in the land battle as that of interdiction. Consequently, to a large extent the lessons from Amiens were responsible for the flawed conduct of Air-Land operations in France and Flanders in 1940 and the resultant catastrophic Allied defeat. However, they also provided the intellectual framework around which the British were able to hone the integrated concepts of Air-Land battle with which they took part in the defeat of Hitler’s forces in the Mediterranean and North Western Europe between 1942 and 1945.
The drift away from close air support during the interwar period has been analysed in several recent studies. David Hall has argued that the primary cause was the short-sighted and conservative view of airpower held within the War Office. He suggests that the Army, unable to grasp the tenets and potential of air power, made successive attempts to gain command of its own aircraft based on the mistaken belief that the aircraft was a tactical battlefield weapon. This argument contains certain elements of merit, not least in highlighting the consistent and not always helpful calls by the War Office for command of its own air component. However, it glosses over several shortcomings in the analysis of the equally command fixated Air Staff in the interwar period which, as will be seen, led to the dysfunctional conduct of Air-Land operations. These shortcomings are more widely acknowledged by Richard Muller. He too highlights the blight placed on the development of close air support by the ongoing and often vitriolic debate over command and control and concludes that the British lacked an ‘. . . intellectual [and] practical foundation for using their air force in support of the army’.
The Battle of Amiens took place at a key moment in the history of the RAF. Although it had been an independent Service since 1 April 1918 with elements conducting a strategic air attack on Germany, by far the greatest proportion of its effort was on the Western Front under the overall control of the British Expeditionary Force (BEF). Each BEF Army commanded an RAF Brigade which comprised of a Corps Wing and an Army Wing. The Corps Wing consisted of squadrons whose main tasks were the control of artillery fire and tactical reconnaissance to give formation HQs as clear a picture as possible of the battle situation as it developed. The Army Wing consisted of fighter-reconnaissance, fighter and bomber squadrons whose task it was to take the battle beyond the front line to both protect the Corps Wing from the German Air Force and attack targets in depth. In addition to the Brigades permanently affiliated to the Armies, GHQ commanded IX Brigade RAF which consisted of two ‘Army’ Wings and a specialist ‘Night operations’ Wing, but which had no permanent command relationship with any Army HQ, being allocated to the sector of the front where the need was greatest as reinforcement. At Amiens, Fourth Army had V Brigade under command with IX Brigade in direct support and support from III Brigade from Third Army, I Brigade from First Army and X Brigade from Fifth Army available if necessary. Furthermore, V Brigade was reinforced with 8 Squadron, which since 1 July 1918, had been permanently attached to the Tank Corps to develop co-operation techniques between the two nascent arms.
The air plan that the RAF attempted to execute at Amiens was ambitious and strikingly modern in concept, consisting of three broad phases. First, the bomber and fighter squadrons of IX Brigade were to achieve air superiority in the attack sector by destroying the German air units already in the battle area on the ground with a surprise dawn attack. The IX Brigade fighters were then to oppose any German air force reinforcements that attempted to join the battle. Second, the Corps and fighter squadrons of V Brigade were to provide close support to the ground formations of Fourth Army as they punched their way through the German defences and then disrupt any attempts the Germans made to deploy their local reserves. Finally, the bomber squadrons were to launch evening attacks on key railway stations to disrupt the arrival of German strategic reserves attempting to reach the battle area.
The weather disrupted the plan from the outset as thick fog shrouded the battle area preventing IX Brigade from completing its attack on the German aerodromes to full effect. However, from around 09.00 hrs onwards, the clearing conditions allowed V Brigade to increasingly influence the battle. In the thick of the action was 8 Squadron whose aircraft maintained a steady stream of information to the Tank Brigades HQs on the progress of the battle. In addition to this task, by 09.50 hrs, it’s aircraft became increasingly involved in the attack on machine guns and field guns being used by German rearguards to hold up the tanks, dropping 81 bombs and firing 6,570 rounds by the close of the day. Alongside 8 Squadron, the fighter squadrons of V Brigade ranged across the battlefield engaging the ‘exceptional targets’ caused by the confusion within the German lines. Numerous attacks were made both on the line of contact between the ground forces and in depth as the German reserve regiments and battalions attempted to move forward. Among other examples, they disrupted the counter-attacks of 27th and 54th Reserve Divisions at Morlancourt and 109th Division at Harbonnières. Similarly, the 119th Division took over nine hours to travel 15 kilometres by lorry to the front line at Vrély, being forced to halt numerous times by incessant aerial attack. The German Second Army was never allowed to make a coherent response against its assailants.
Whilst V Brigade was completing its mission in support of Fourth Army, the plan for the air battle took a fundamental change of direction. Pilots flying over the battlefield had noticed major traffic congestion around the bridges over the River Somme approximately 15 kilometres behind the front line. Consequently, around midday, Major-General Salmond, GOC RAF, cancelled the planned bombing missions of the railways and redirected IX Brigade to mount attacks, with both bombers and bomb-armed fighters, on the bridges in an attempt to cut the German lines of communication. The attacks met with little success as the bridges proved difficult targets to hit and the bombs that were used lacked the power to cause any major structural damage. Furthermore, the removal of the IX Brigade fighters from their counter air task coincided with the arrival of significant German air reinforcements, in particular the elite air combat specialist Jagdgeschwader units flying in from Champagne. The ensuing air battle raged over the next two days as IX Brigade attempted in vain to destroy the bridges. Only on 10 August did the Brigade admit defeat and revert back to the original task of interdicting the railway system.
Analysis of the air Battle at Amiens was swift and, unsurprisingly given the acute need of the BEF to maintain its operational tempo, paid particular attention to the conduct of close air support. The vulnerability of tanks to anti-tank guns once they had outrun their artillery support was of great concern as noted by both the 4 and 5 Tank Brigades. The belief that aircraft could neutralize this threat was one of the primary lessons taken to heart by V Brigade after the battle. On 14 August Brigadier Charlton circulated a memorandum to his squadrons, highlighting the importance of this new task, stating that, ‘. . . it will be seldom that the duty in which machines are at the moment engaged will not yield in importance to offensive action against the anti tank gun’. His perspective was reinforced by 22nd Wing’s report on the close air support given by its fighter squadrons during the battle, submitted on 19 August. One of its key recommendations highlighted the necessity for close liaison with Tank units to optimize the effectiveness of fighter aircraft engaged in attacking anti-tank defences. Action was swift and within two days 73 Squadron, equipped with Sopwith Camels, was removed from IX Brigade and grouped with 8 Squadron in order to specialize in ground attack with single-seat fighters. This small ‘group’ spent the remainder of the war in permanent support of the Tank Corps, moving flights across the BEF as they followed the tanks. Ground attack also became a higher priority for 8 Squadron as a policy change reduced the number of aircraft allocated to contact patrol work to the minimum necessary, with the remainder diverted to attack anti-tank guns. Furthermore, command and control was improved through the use of wireless telegraphy to enable the engagement of fleeting targets. This system integrated the efforts of the Corps and Army Wings more effectively and provided significant assistance to the later battles at Bapaume (23 August), the Hindenburg Line (27–9 September) and Le Cateau (8 October).
By the time of the Armistice in November 1918, the RAF had become a sophisticated exponent of air power in support of ground forces, complementing its unique roles in the strategic arena. Unfortunately, this situation was not maintained in the interwar period as inter-Service rivalry and senior officer prejudice relegated this capability in importance to the extent that by 1930 it had almost ceased to exist. Only with the rise of the nascent Continental threats in the mid-1930s did the concept of an integrated Air-Land battle re-emerge.
The erosion of Air-Land capability resulted chiefly from two factors; fiscal constraints and inter-Service rivalry. The austere post-war fiscal context ensured that the defence budget was so low that the individual Services struggled to maintain sufficient resources to meet their many requirements. These difficulties were apparent from 1918 onwards as Defence and social reform programmes competed for funds provided by a reduced GDP that was 13 percent lower in 1921 than it had been in 1913, and undermined by the increased annual cost of servicing the national debt which jumped from £24.5M in 1913 to £344.5M in the 1920s. In such circumstance major economies needed to be made in a significantly restructured national budget. Within a year of the signing of the Armistice the Cabinet instituted the cardinal assumption that Britain would not be engaged in a great war within ten years and that no Expeditionary Force would be required for this role; the so-called Ten Year Rule. This allowed the Treasury to drastically cut the Defence vote from £616M in 1919/20 to £232M in 1920/21. This process was continued by subsequent Governments until 1931/32 when the allocation to defence was £107M.
One of the major consequences of this retrenchment was an increased level of rivalry between the Services. Whereas co-operation had been one of the hallmarks of success in the relatively resource-rich context of 1918, by the early 1920s inter-Service relations became increasingly adversarial. Under the leadership of the Chief of the Air Staff (CAS), Trenchard, the RAF defended itself by claiming that airpower could substitute for the manpower-intensive roles previously conducted by the other Services when Sir Eric Geddes conducted his review of National Expenditure. Alongside the role of ‘Air Policing’ of the Empire, Trenchard and his staff also developed an embryonic Continental strategy built on the delivery of a strategic air attack on vital centres of production. In this way an enemy nation would be prevented from bringing its potential strength to bear on the battlefield. Although there appears to have been some confusion within the Air Staff as to how this would be achieved, a crucial element of this debate was Trenchard’s view that air superiority would be an essential precondition. In the prevailing financial climate, the RAF would not have the resources to fulfil all its potential tasks and in prioritizing its new roles over the old, the RAF’s shift away from close support began.
Trenchard’s position was articulated in the first formal document to deal with the issue of Air-Land battle, Confidential Document (CD) 21, published in June 1921. This document contained a section discussing the tactical roles of aircraft operating in support of the Army, describing an organizational and operational concept identical to that used in November 1918. Unsurprisingly, when discussing the use of aircraft for offensive action the document stated that aircraft were, ‘. . . very valuable to silence anti tank guns . . .’, and that widespread bombing of the battlefield was to be discontinued a few hours after zero in order to ‘. . . concentrate on main routes . . .’.
However, while this section may have placated the Army, Trenchard’s vision was articulated in the following pages. Part II of CD 21 was introduced by the exposition that the primary role of air power was, ‘. . . air fighting, air defence against a continental or other threat, [and] aerial bombardment of enemy establishments’. This represented a point of departure from the status quo by the RAF. Although part I described the concept of air support in its established form, the assertion that air power’s primary role lay elsewhere would by implication result in the relegation of tasks in support of the other two Services.
The drift away from Army support tasks was even more pronounced in Confidential Document 22 (CD22), The Operations Manual RAF, published in 1922. This publication was a much more detailed articulation on how the RAF was to operate on deployment than its predecessor. Although it acknowledged the requirement for co-operation with the Army by including an entire chapter on the subject, the close support role was now formally subordinated to the perceived primacy in the need to gain air superiority. This shift towards the air superiority role had two major implications, both of which undermined the delivery of air support to the Army. First, despite acknowledging the utility of air power in countering anti-tank defences and stating that the best aircraft to undertake this role was the single-seat fighter, in order to maintain the flexibility to concentrate forces onto the air superiority task, CD22 also directed that role specialization for these aircraft be minimized. This represented a significant shift away from the combat-proven experience of the air units and formations that fought at Amiens that would almost certainly result in a degradation of close support capability. The second implication was that aircraft earmarked for gaining air superiority were unlikely to be risked on the lower priority task of low-flying attacks which, it was understood, would result in exceedingly high casualties.