Cap badge 3rd Bat Monmouthshire Regiment

With the outbreak of war in August 1914 the Territorial Force was mobilised. In all the Monmouthshire Regiment formed battalions, most of which fought on the Western Front, during the conflict as follows:

• 1/1st (Rifle) Battalion: redesignation of 1st Battalion in September 1914 on formation of second-line 2/1st Battalion. Transferred to 84th Brigade of the newly formed 28th Division in France in February 1915, it soon saw service in the Second Battle of Ypres, suffering severe casualties. In May 1915 it was temporarily amalgamated with the 1/2nd and 1/3rd Battalions at Vlamertinghe in Flanders to form a composite unit. Brought up to strength with replacements, the 1/1st resumed its own identity in August 1915. In September 1915 it was assigned to the 46th (North Midland) Division as a pioneer battalion. It remained with the division for the rest of the war, and was at Avesnes in northern France at the time of the Armistice of 11 November 1918.^[1][4][5]
• 2/1st (Rifle) Battalion: formed as a second-line duplicate of the 1st Battalion in Newport in September 1914. It did not move outside the United Kingdom, performing home defence duties, mostly in Suffolk, as part of the 53rd and 68th Divisions. It was disbanded at Lowestoft in March 1918.^[4][5]
• 3/1st (Rifle) Battalion: formed as a "third-line" duplicate of the 1st Battalion in February 1915. It remained in the United Kingdom (in Shropshire and Flintshire). In April 1916 it was redesignated as the 1st (Reserve) Battalion.
  
• 1/2nd Battalion: redesignation of 2nd Battalion in September 1914 on formation of second-line 2/2nd Battalion. Transferred to the 12th Brigade, 4th Division in France in November 1914. It spent the winter taking part in trench warfare near Armentières. It subsequently took part in the Second Battle of Ypres in April and May 1915, fighting alongside the 1/1st and 1/3rd Monmouths in the 28th Division. Such were the losses that the three battalions were temporarily amalgamated. By July 1915 the 1/2nd had been brought up to strength and resumed its own existence. It transferred to the 29th Division as a pioneer battalion. It stayed in this role for the rest of the conflict, ending the war near Renaix in Belgium. It formed part of the army of occupation of Germany before returning to Pontypool where it were disbanded in June 1919.
  
• 2/2nd Battalion: formed as a second-line duplicate of the 2nd Battalion in Pontypool in September 1914. Its service and stations were identical with those of the 2/1st Battalion. It was disbanded at Lowestoft in April 1918.
  
• 3/2nd Battalion: formed as a "third-line" duplicate of the 2nd Battalion in February 1915. Its service and stations were identical with those of the 3/1st Battalion. In April 1916 it was redesignated as the 2nd (Reserve) Battalion and in September 1916 was absorbed by the 1st (Reserve) Battalion.
  
• 1/3rd Battalion: redesignation of 3rd Battalion in September 1914 on formation of second-line 2/3rd Battalion. Transferred to the 83rd Brigade of the newly formed 28th Division in France in February 1915, fought alongside 1/1st and 1/2nd Battalions at the Second Battle of Ypres, due to losses it was temporarily amalgamated with the 1/1st and 1/2nd Battalions. Brought up to strength with replacements, the 1/3rd resumed its own identity in August 1915. In September 1915 it was assigned to the 49th (West Riding) Division as a pioneer battalion. In 1916 it became GHQ troops. Due to the fact that many men in Monmouthshire were engaged in the vital wartime industries of coal-mining and steel making, it was found increasingly difficult to find drafts to reinforce the battalion, and on 31 August 1916 it were disbanded with troops transferred to the 1/1st and 1/2nd Battalions.
  
• 2/3rd Battalion: formed as a second-line duplicate of the 3rd Battalion in Abergavenny in September 1914. Its service and stations were identical with those of the 2/1st and 2/2nd Battalions. It was disbanded at Herringfleet in August 1917, with troops transferred to 2/1st and 2/2nd Battalions.
  
• 3/3rd Battalion: formed as a "third-line" duplicate of the 3rd Battalion in February 1915. Its service and stations were identical with those of the 3/1st Battalion. In April 1916 it was redesignated as the 3rd (Reserve) Battalion and in September 1916 was absorbed by the 1st (Reserve) Battalion.
  
• 4th Battalion: a redesignation of the 48th Provisional Battalion, Territorial Force in January 1917. This unit had been formed in June 1915 from personnel of the Monmouthshire and Herefordshire Regiments ineligible for service overseas. Stationed in Norfolk.