The 55th (West Lancashire) Division was an infantry division of the British Army's Territorial Force (TF) that saw extensive combat during the First World War. It was raised initially in 1908 as the West Lancashire Division. Following the outbreak of the First World War, in 1914, the majority of the division's men volunteered for overseas service. Those who did not volunteer were used to form new reserve units, and on 31 August 1914 these were used to create the 2nd West Lancashire Division. Rather than being deployed as a whole formation, the West Lancashire Division was broken up during 1914 and 1915, as its troops were dispatched piecemeal to the Western Front. As each left, they were replaced by reserves. When the last volunteers departed for overseas service, the remnant of the division was amalgamated with the 2nd West Lancashire Division, and the West Lancashire Division ceased to exist.

In 1916, the division was reformed in France as the 55th (West Lancashire) Division and was reassigned its original units. During the Battle of the Somme, the division fought several actions at Guillemont, Ginchy, and Morval. In 1917, the division fought at Pilckem and the Menin Road Ridge, during the Battle of Passchendaele, and gained an excellent reputation. Late in 1917, the division fought in the Battle of Cambrai. Towards the end of the battle, a major German counterattack forced the division back over . A court of inquiry was convened to examine this loss of territory and the division's conduct. The inquiry delivered findings that proved controversial with contemporary soldiers and modern historians. In 1918, the division faced the German spring offensive, and conducted a much-lauded defence of Givenchy during the Battle of Estaires. After the German offensive stalled, the division joined in the Hundred Days Offensive, the culminating offensive of the war. The division suffered almost 36,000 casualties, with 6,520 killed, in over two years of combat. After the end of hostilities, the division was slowly demobilised and eventually disbanded in 1919. In 1920, the division was reformed in England.

Formation In 1901, following lessons learnt from the Second Boer War and increased tension with the German Empire, the United Kingdom sought to reform the British Army to fight a European adversary. This task fell to Secretary of State for War, Richard Haldane, who implemented the Haldane Reforms. The Territorial and Reserve Forces Act 1907 created a new Territorial Force (TF) by merger of the Yeomanry and the Volunteer Force in 1908. This resulted in the creation of 14 divisions, included the West Lancashire Division. Each division was to be around 18–19,000 men strong. However, the TF was never able to recruit sufficient numbers of men to achieve this uniformly. The territorials were liable to serve only in the United Kingdom, and the divisions would take over the defence of the country when the regular army was abroad on military service. In 1910, the Imperial Service Obligation was introduced. This allowed territorials to volunteer for overseas service before any national emergency. Haldane saw the primary function of the TF as a way to expand the British expeditionary forces and was confident that up to a quarter of the men would volunteer on mobilisation. It was expected that on the outbreak of war, it would take the TF divisions up to six months to come up to an acceptable training standard.

Major-General Edward Dickson commanded the new division composed of the North Lancashire, Liverpool and South Lancashire Brigades. The division recruited from Lancashire, which then included what is now Merseyside, parts of Cheshire, Greater Manchester, and southern Cumbria. The divisional headquarters, two brigade headquarters, most of the divisional artillery (with elements at Seaforth Barracks), elements of other divisional assets, and five infantry battalions were based in Liverpool. The rest of the division was spread out, with garrisons in Blackpool, Blundellsands, Kendal, Lancaster (including the North Lancashire Brigade headquarters), Southport, St Helens, Warrington, and Widnes. In July 1909, the division was inspected by Edward VII at Knowsley. A month later, it began its first annual training camp at Caerwys, Wales. It was the first Territorial division to conduct field training.

French Hippolyte Langlois watched and reviewed the division during this training. Langlois lauded the soldiers' use of terrain, initiative, stamina, a unit cohesion he believed was founded on civilian life relationships, and morale and motivation that he saw coming from a sense of patriotism. His criticisms included limited technical and tactical proficiency, especially within the Royal Field Artillery units. He believed the flaws were due in part to the small training areas available and inadequate live fire practice. Langlois believed the division capable of meeting the TF mandate of repelling an invasion. The historian Ian Beckett commented there were deficiencies with the force: in 1910 "a third ... had failed the modest musketry requirements of firing off 23 rounds"; in 1912, around two-thirds had completed their required training, and divisions failed to retain soldiers. The historian Kevin Mitchinson wrote there were pre-war concerns that members of the division were not physically fit enough to soldier, that the division "was not particularly highly rated", and was 2,900 men below establishment in 1914.

First World War Early years Due to their proximity, the pre-war deployment plan for the West and the East Lancashire Divisions was to be deployed to Ireland to relieve regular army formations. At the outbreak of the First World War in 1914, the West Lancashire Division returned from its annual training in Wales to barracks and depots in Lancashire. Advanced elements were to depart for Ireland to establish billets at various locations, including Limerick. This move was called off on 5 August, and five days later it was announced that local Irish reserve forces would ideally relieve the regular army formations instead. The cancellation resulted mostly from the logistical difficulties of transporting inbound and outbound troops, and a lack of equipment and transport between the two Lancashire divisions. Mitchinson wrote an extra dimension existed, as "there was concern among the authorities that some of the King's Liverpool battalions might have rather too much sympathy with potentially rebellious sections of Irish society".

With the move to Ireland cancelled, the division was immediately dispersed around the country. The South Lancashire Brigade went to bolster defences around the Firth of Forth, Scotland; the Liverpool Brigade was assigned to Central Force and moved to Canterbury, Kent; other elements of the division went to Oxfordshire. The men in England were used to guard vulnerable points, including railway lines, bridges, and tunnels. With popular enthusiasm for the war high, potential recruits flooded the division's regimental depots. The divisional historian, James Ogden Coop, wrote, "every existing vacancy was filled and could have been filled ten times over". Some of these recruits were used to bring the East Lancashire Division up to strength. The dispersion of the division affected training, which for some units was impossible to undertake. Following the outbreak of the war, on 13 August 1914, Secretary of State for War Lord Kitchener signalled a willingness to deploy territorial units overseas in which 80 per cent of the men (reduced to 60 per cent at the end of the month) had volunteered. Coop wrote "every unit in the division volunteered". Two days later, the division was ordered to separate those who had volunteered from those who had not. The latter were used to form reserve units. On 31 August, these reserve formations coalesced to become the 2nd West Lancashire Division, which was based initially at the West Lancashire Division's peacetime barracks and depots.

The all-volunteer West Lancashire Division went through a succession of general officers commanding (GOC) before Major-General John Forster was given command on 3 September 1914. Because of the casualties suffered by the British Expeditionary Force (BEF) during the opening months of fighting on the Western Front, the division's volunteers were used as reinforcements. Between October 1914 and May 1915, the division was steadily drained; companies of engineers, artillery, medical personnel, and battalions of infantry were removed from the division to reinforce other divisions. The Commander-in-Chief, Home Army, General Ian Hamilton, questioned the wisdom of using the division this way as he believed the men were "'fully 20% behind the rest' in efficiency and training". However, he believed the deployment of intact battalions would not affect their esprit de corps, as he perceived there being a loyalty greater to the battalion rather than the division. As battalions departed, reserve units from the 2nd West Lancashire Division replaced them. In April 1915, the North Lancashire Brigade, the division's last remaining infantry formation of volunteers, was transferred to the 51st (Highland) Division. The rest of the West Lancashire Division was then amalgamated into the 2nd West Lancashire Division, based around Canterbury, and the former division ceased to exist.

In November 1915, the Army Council authorised the reformation of the division in France, and provided a new designation: the 55th (West Lancashire) Division. Beginning on 3 January 1916, the division's former units assembled near Hallencourt. This included the arrival of the North Lancashire Brigade, which had been renumbered as the 164th Brigade in 1915. The Liverpool and South Lancashire Brigades were reformed, but numbered as the 165th and the 166th Brigades respectively. On 27 January 1916, the reformation was completed, and Major-General Hugh Jeudwine was assigned as commander. These experienced troops were no longer completely made up of the men who had left in 1915, due to casualties and new drafts. By the end of March, the division was still 3,000 men under establishment. The division comprised three brigades: the 164th Brigade, consisting of the 1/4th Battalion, King's Own (Royal Lancaster Regiment) (1/4KORL), the 1/4th Battalion, Loyal North Lancashire Regiment (1/4LR), the 2/5th Battalion, Lancashire Fusiliers (2/5LF) and the 1/8th (Irish) Battalion, King's (Liverpool Regiment) (Liverpool Irish); the 165th Brigade consisted of the 1/5th Battalion, King's (Liverpool Regiment) (1/5KR), the 1/6KR, the 1/7KR, and the 1/9KR; and the 166th Brigade consisted of the 1/10th (Scottish) Battalion, King's (Liverpool Regiment) (Liverpool Scottish), the 1/5th Battalion, the South Lancashire Regiment (1/5SL), the 1/5th Battalion, King's Own (Royal Lancaster Regiment) (1/5KORL) and the 1/5th Battalion, Loyal North Lancashire Regiment (1/5LR). During 1916, Jeudwine adopted the Red Rose of Lancaster as the divisional emblem, to foster county pride in the division. The insignia inspired the creation of a poem that ended with "We win or die who wear the rose of Lancaster". This line was then adopted as the divisional motto.

First trench tour

On 16 February 1916, the division took over a sector of the front line between Brétencourt and Wailly, near Arras, and relieved the French 88th Division. They held this area until July, and carried out several trench raids. The Liverpool Irish launched the first on 17 April. Attacking at night, the battalion inflicted significant damage; its 56 casualties included the loss of Second Lieutenant Edward Felix Baxter. For his actions during the raid, Baxter earned the Victoria Cross (VC), the highest gallantry award available to British military personnel. A further VC was awarded to Private Arthur Procter in the aftermath of a raid on the night of 3/4 June.