121st Brigade was a New Army or 'Kitchener's Army' formation raised in October 1915, in 40th Division at Aldershot. An earlier 121 Brigade had been raised in late 1914 as part of the 'Fifth New Army', but when the Fourth New Army was broken up in April 1915 to provide reserve units for the First to Third New Armies, the formations of the Fifth took their place, and the original 121 Bde was renumbered 116th Brigade. By the time the new 120 Bde was organised the flow of volunteers had dwindled, and the standard of height for infantry soldiers had been lowered in order to encourage recruitment. Some of these so-called 'bantams' were well-knit, hardy men, but many others, especially in 121st Bde, were under-developed and unfit. It was estimated that the four battalions in the brigade would provide enough fit men for only two serviceable battalions. To prevent the departure of the division to the Front being indefinitely postponed, the divisional commander asked for fresh units to be drafted in. 121st Brigade was completely reorganised in February 1916. Divisional training was then intensified and the division was warned for overseas service in May 1916.
20th Battalion Middlesex Regiment – from 118 Bde February 1916
21st Battalion Middlesex Regiment – from 118 Bde February 1916
121st Brigade Machine Gun Company – joined June 1916
121st Trench Mortar Battery – formed in France June 1916
Training
Divisional organisation and training was delayed because some of the brigades contained a large proportion of under-developed and unfit men. 121st Brigade had to undergo a drastic weeding-out and the drafting in of new battalions before it was fit for service. This was completed in February 1916. Divisional training was then intensified and it was warned for overseas service in May 1916. Disembarkation was carried out at Le Havre between 2 and 6 June, and 40th Division concentrated in the Lillers area by 9 June ready to take its place in the line. Units went into the trenches attached to formations of I Corps for familiarisation, and then the division took over its own section of line.
Operations
121 Brigade's active service was entirely spent on the Western Front. During 1917 it took part in the following actions:
In February 1918, British brigades were reduced to a three-battalion basis and brigade machine gun companies were combined into divisional battalions. 21st Middlesex transferred to 119th Bde in 40th Division, and 121 MG Company joined 40th Bn Machine Gun Corps. The reorganised brigade took part in the following actions:
Following heavy casualties during the German Spring Offensive of 1918, 40th Division was reduced to two composite brigades. 1st Composite Brigade formed under Brig-Gen J. Campbell of 121 Bde on 18 April had the following composition:
1st Composite Bde was employed on digging the Herzelee–le Brearde Line in front of Cassel. In early May 1918, all of 40th Division's remaining infantry battalions were reduced to training cadres and were posted to other formations while the trench mortar batteries disbanded. On 6 May 1918, 121 Bde's three infantry battalions were reduced to cadre and were posted away, and the trench mortar battery disbanded.
Reconstituted
40th Division began to reform on 14 June 1918, and between 18 and 20 June three battalions were transferred from 59th Division to reconstitute 121 Bde:
On 13 July the term 'Garrison' was dropped from the battalion titles, and the brigade light trench mortar battery had been reformed. By 18 July the brigade resumed its place in the Front Line. The reconstituted brigade took part in the following actions:
After the Armistice, the division was engaged in road repair and refresher courses for men returning to civilian trades. Demobilisation proceeded rapidly during January and February 1919, and its units were reduced to cadre strength by March. The final cadres disappeared during May.
Commanders
The following officers commanded 121 Brigade during the First World War:
121 Brigade was never reformed, but the number was used for deception purposes during the Second World War. 30th Battalion Norfolk Regiment, a line of communication unit serving in 43rd Brigade in Sicily and composed mainly of men below Medical Category 'A', was redesignated '121st Infantry Brigade' and acted as if it were a full brigade in an equally fictitious '40th Infantry Division' from November 1943 until May 1944.
