Field Marshal Alan Francis Brooke, 1st Viscount Alanbrooke (23 July 1883 – 17 June 1963), was a senior officer of the British Army. He was Chief of the Imperial General Staff (CIGS), the professional head of the British Army, during the Second World War, and was promoted to field marshal on 1 January 1944.

Brooke trained as an artillery officer and became Commandant of the School of Artillery, Larkhill in 1929. He held various divisional and corps level commands before the Second World War and became C-in-C Home Forces in 1940.

Brooke became Chief of the Imperial General Staff in 1941. In that role he focused on strategy and, in particular, on the Mediterranean theatre. Here, his principal aims were to rid North Africa of Axis forces and knock Italy out of the war, thereby opening up the Mediterranean for Allied shipping. This progress in the Mediterranian allowed the cross-Channel invasion from southern England to Normandy in France when the Allies were ready and the Germans sufficiently weakened. He then developed the strategy for pushing back the German forces from Normandy across France and finally into Germany itself. As chairman of the Chiefs of Staff Committee, Brooke was the foremost military advisor to Prime Minister Winston Churchill, and had the role of co-ordinator of the British military efforts in the Allies' victory in 1945.

After retiring from the British Army, Brooke served as Lord High Constable of England during the Coronation of Queen Elizabeth II in 1953. His "war diaries" are famous for their criticism of some of Churchill's policies and for Brooke's forthright views on other leading figures of the war.

Background and early life Alan Brooke was born on 23 July 1883 at Bagnères-de-Bigorre, Hautes-Pyrénées, to a prominent Anglo-Irish family from West Ulster. The Brookes had a long military tradition as the "Fighting Brookes of Colebrooke", with a history of service in the Wars of the Three Kingdoms, the French Revolutionary and Napoleonic Wars, and World War I. He was the seventh and youngest child of Sir Victor Brooke, 3rd Baronet, of Colebrooke Park, Brookeborough, County Fermanagh, and the former Alice Bellingham, second daughter of Sir Alan Bellingham, 3rd Baronet, of Castle Bellingham in County Louth., p 12. Brooke's father died when he was just eight years old.

Brooke was educated at a day school in Pau, France, where he lived until the age of 16; he was bi-lingual in French (which he spoke with a heavy Gascon accent and spoke as a first language as a result of his upbringing in the French Pyrenees) and English., p 14. He spoke both French and English very fast, leading some Americans later in life to distrust a "fast-talking Limey." He was also fluent in German, and had learnt Urdu and Persian., pp.41,44,51.

Brooke, desiring a military career, "only just" qualified for the Royal Military Academy, Woolwich in 1900, coming sixty-fifth out of seventy-two in the entrance exam, but passed out at seventeenth. Had he done any better he would have qualified for a commission in the Royal Engineers, as was his initial intention, and possibly would not have ended up on the General Staff after the Great War.

Brooke was commissioned into the Royal Regiment of Artillery as a second lieutenant on 24 December 1902. Due to his high placing at Woolwich, Brooke was allowed to choose which branch of the Royal Artillery to join. His choice was the Royal Field Artillery, with which he served in Ireland and India in the years leading up to the outbreak of the First World War in the summer of 1914. He also "received his jacket" upon being selected to join the Royal Horse Artillery.

First World War

During the war, he was assigned to an ammunition column of the Royal Horse Artillery on the Western Front, where he gained a reputation as an outstanding planner of operations. He later was transferred to the 18th Division. At the Battle of the Somme in 1916, he introduced the French "creeping barrage" system, thereby helping the protection of the advancing infantry from enemy machine gun fire., pp. 72–73. Brooke was with the Canadian Corps from early 1917 and planned the barrages for the Battle of Vimy Ridge. In 1918 he was appointed GSO1 as the senior artillery staff officer in the First Army.Vimy Ridge: A Canadian Reassessment, edited by Geoff Hayes, pp. 98–99. Brooke ended the conflict as a lieutenant-colonel and a Companion of the Distinguished Service Order and Bar and was mentioned in despatches six times.

As with many others of his generation, the war left its mark upon Brooke. In October 1918, shortly before the Armistice of 11 November 1918, he wrote

When the Armistice did eventually arrive Brooke was in London on leave. He watched the crowds of people celebrating but felt mixed feelings, as he himself later wrote:

On 31 March 1942 he wrote:

Between the wars During the interwar period, Brooke attended the first post-war course at the Staff College, Camberley in 1919. He managed to impress both his fellow students and the college's instructors during the relatively brief time he was there. He then served as a staff officer with the 50th Division from 1920 to 1923. Brooke then returned to Camberley, this time as an instructor, before attending the Imperial Defence College. He was later appointed as an instructor at the college, and while there he became acquainted with most of the officers who became leading British commanders of the Second World War. From 1929 onwards Brooke, promoted on 1 June 1935 to major general, held a number of important appointments: Inspector of Artillery, Director of Military Training and then General Officer Commanding (GOC) of the Mobile Division (later the 1st Armoured Division) in 1935. In 1938, on promotion to lieutenant-general, he took command of the Anti-Aircraft Corps (renamed Anti-Aircraft Command in April 1939) and built a strong relationship with Air Chief Marshal Hugh Dowding, the AOC-in-C of Fighter Command, which laid a vital basis of co-operation between the two commands during the Battle of Britain the following year. In July 1939 Brooke moved to command Southern Command. By the outbreak of the Second World War, Brooke was already seen as one of the British Army's foremost generals., p. 78.

Second World War Commander in Flanders, France and Britain

Following the outbreak of the Second World War, in September 1939, Brooke commanded II Corps in the British Expeditionary Force (BEF)—which included in its subordinate formations the 3rd Infantry Division, commanded by the then Major-General Bernard Montgomery, as well as Major-General Dudley Johnson's 4th Infantry Division. As corps commander, Brooke had a pessimistic view of the Allies' chances of countering a German offensive. He was sceptical of the quality and determination of the French Army, and of the Belgian Army. This scepticism appeared to be justified when he was on a visit to some French front-line units and was shocked to see unshaven men, ungroomed horses and dirty vehicles.Reagan, Geoffrey. Military Anecdotes (1992) p. 166, Guinness Publishing

He had also little trust in Lord Gort, Commander-in-Chief of the BEF, who Brooke thought took too much interest in details while being incapable of taking a broad strategic view. Gort, on the other hand, regarded Brooke as a pessimist who failed to spread confidence, and was thinking of replacing him., pp. 135–140. Brooke correctly predicted that the Allied powers' Plan D envisioning an advance along the Meuse would allow the Wehrmacht to outflank them, but British High Command dismissed his warnings as defeatist.

When the German offensive began, Brooke, aided by Neil Ritchie, his Brigadier General Staff (BGS), distinguished himself in the handling of the British forces in the retreat to Dunkirk. His II Corps faced rapid German Army armoured advances following the Allied defeat at the Battle of Sedan. In late May 1940 it held off the major German attack on the Ypres-Comines Canal but then found its left flank exposed by the capitulation of the Belgian army. Brooke swiftly ordered Montgomery's 3rd Division to switch from the Corps' right flank to cover the gap. This was accomplished in a complicated night-time manoeuvre. Pushing more troops north to counter the threat to the embarking troops at the Dunkirk evacuation from German units advancing along the coast, II Corps retreated to their appointed places on the east or south-east of the shrinking perimeter of Dunkirk., pp. 78–79. Brooke's actions not only saved his own forces from capitulation, but prevented the Germans from seizing the 20-mile gap left by the Belgian surrender and capturing the entire BEF before it could safely evacuate.

Then on 29 May Brooke was ordered by Gort to return to England, leaving the Corps in Montgomery's hands. According to Montgomery, Brooke was so overcome with emotion at having to leave his men in such a crisis that "he broke down and wept" as he handed over to Montgomery on the beaches of La Panne., p. 235. He was told by Gort to "proceed home ... for (the) task of reforming new armies" and so returned on a destroyer (30 May). Then "on June 2nd set out for the War Office to find out what I was wanted for" with a "light heart" and with no responsibility, and was then told by John Dill (CIGS) that he was to "return to France to form a new BEF"; he later said that hearing the command from Dill was "one of his blackest (moments) in the war". He had already realised that there was no hope of success for the "Brittany plan" (Breton redoubt) to keep an allied redoubt in France. After General Maxime Weygand warned him that the French Army was collapsing and could offer no further resistance, he decided that he needed to convince his superiors to allow him to withdraw his forces to Cherbourg and Brest for evacuation to Britain. He told Secretary of State for War Anthony Eden that the mission had "no military value and no hope of success" although he could not comment on its political value., pp.163-167. In his first conversation with Prime Minister Winston Churchill (Brooke had been rung by Dill who was at 10 Downing Street) he insisted that all British forces should be withdrawn from France. Churchill initially objected but was eventually convinced by Brooke; around 200,000 British and Allied troops were successfully evacuated from ports in northwestern France.Brooke, p. 2 in , entres 29 May & 14 June 1940., pp. 51–53.

Home Forces After returning for a short spell at Southern Command Brooke was appointed in July 1940 Commander-in-Chief, Home Forces, with orders to take charge of anti-invasion preparations. Thus it would have been Brooke's task to direct the land battle in the event of a German amphibious invasion of Great Britain. Contrary to his predecessor General Sir Edmund Ironside, who favoured a static coastal defence, Brooke developed a mobile reserve which was to swiftly counterattack the enemy forces before they were established. A light line of defence on the coast was to assure that the landings were delayed as much as possible. Writing after the war, Brooke acknowledged that he also "had every intention of using sprayed mustard gas on the beaches"., entry 22 July 1940., pp.172–186.

Brooke believed that the lack of a unified command of the three services was "a grave danger" to the defence of the country. Despite this, and the fact that the available forces never reached the numbers he thought were required, Brooke considered the situation far from "helpless" if the Germans were to invade. "We should certainly have a desperate struggle and the future might well have hung in the balance, but I certainly felt that given a fair share of the fortunes of war we should certainly succeed in finally defending these shores", he wrote after the war., entries for 29 July and 15 September 1940., pp.178–184. But in the end, the German invasion plan was never taken beyond the preliminary assembly of forces.