British Fifth Army

British Fifth Army
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Unit name	Fifth Army (British Empire)
Dates	1916–1919
Country	United Kingdom
Allegiance	British Empire
Branch	British Army
Type	Field army
Role	Offensive operations
Size	Army
Command structure	British Expeditionary Force
Garrison	France
Notable commanders	General Sir Hubert Gough, General Sir William Peyton

British Fifth Army was a field army of the British Army active on the Western Front during the later stages of the First World War. Formed from the reserve formations of the British Expeditionary Force, it conducted several major offensive and defensive operations during 1916–1918 before being disbanded after the armistice. The army's operations intersected with numerous campaigns, battles, and corps of the Western Front, linking it to commanders, divisions, and allied formations from the French Army and United States Army.

Formation and Early History

The Fifth Army was created in 1916 from the re-designation of the Reserve Corps that had been formed after the Battle of the Somme to control the growing number of BEF formations. Its initial formation involved transferring headquarters elements from the Reserve Army and coordinating with corps such as X Corps, III Corps, and XVIII Corps. The headquarters worked closely with staff officers who had served at GHQ BEF, liaised with the French High Command during preparations for combined operations, and incorporated divisions recently engaged at Arras, Messines, and the Third Battle of Ypres.

First World War Campaigns

Under commanders who had previously led at Battle of the Somme and Arras Offensive, the Fifth Army took part in the German Spring Offensive of 1918, notably during the Battle of St Quentin and the Bapaume sector retreats. Facing forces from the German Empire including units from the German Army, the army endured breakthroughs at locations such as Saint-Quentin and Péronne, which forced withdrawals that affected neighboring formations like Third Army and Fourth Army. During the summer and autumn counter-offensives, the Fifth Army participated in the Hundred Days Offensive, cooperating with formations from the French Army, the United States Army, and the Belgian Army in battles including the Battle of Amiens and advances toward Cambrai and the Hindenburg Line. Its operations involved coordination with corps-level commands such as XV Corps and IV Corps and included engagements near Ypres and along the Somme.

Organisation and Command

Command of the Fifth Army was given initially to senior officers who had served in key BEF roles; its most prominent commander was General Sir Hubert Gough, whose previous commands included corps and army-level formations. Later leadership included General Sir William Peyton and senior staff who had worked under commanders at GHQ BEF and in liaison with the Admiralty and War Office for strategic planning. The army contained multiple corps such as XIII Corps, XXIII Corps, and numerous divisions—regular, territorial, and service—many of which had distinguished service at Gallipoli, Battle of Loos, and Cambrai (1917). Its order of battle evolved as divisions were transferred between the Fifth Army, Fourth Army, and allied commands; staff officers coordinated artillery from Royal Artillery brigades and Royal Flying Corps squadrons that later became part of the Royal Air Force.

Postwar Disbandment and Legacy

Following the Armistice of 11 November 1918, the Fifth Army oversaw demobilisation tasks, rear-area security, and the repatriation of troops in concert with the Ministry of Pensions and the War Office. It was gradually disbanded as formations were reduced and returned to the United Kingdom or transferred to occupation duties with the British Army of the Rhine. The army's actions during the Spring Offensive and the Hundred Days Offensive influenced postwar analysis by staffs at Staff College, Camberley and led to doctrinal reviews that informed interwar exercises and revisions adopted by the British Army and allied planners. Memorials and regimental histories referencing units that served under the army appear in museums such as the Imperial War Museum, regimental museums, and local commemorations in places like Somme and Ypres.

Category:Field armies of the British Army Category:Military units and formations established in 1916 Category:Military units and formations disestablished in 1919