List of battalions of the Durham Light Infantry

This is a list of battalions of the Durham Light Infantry, which existed as a regiment of the British Army from 1881 to 1968.

Original composition
When the 68th Regiment of Foot and the 106th Regiment of Foot became the Durham Light Infantry (DLI) in 1881 under the Cardwell-Childers reforms of the British Armed Forces, seven pre-existent militia and volunteer battalions of County Durham were integrated into the structure of the DLI. Volunteer battalions had been created in reaction to a perceived threat of invasion by France the late 1850s. Organised as "rifle volunteer corps", independent of the British Army and composed primarily of the middle class, they underwent a number of reorganisations before reaching the form in which the were incorporated into the county regiment.

In 1887 the Durham Rifle Volunteer Battalions were renamed as Volunteer Battalions of the Durham Light Infantry retaining their numbers.

Reorganisation
The Territorial Force (renamed the Territorial Army in 1920) was formed in 1908, which the volunteer battalions joined, while the militia battalions transferred to the "Reserve" or the "Special Reserve", the 3rd and 4th battalions exchanged numbers and were recast as the 3rd (Reserve) and 4th (Extra Reserve) battalions in a draft finding role. The reason for this apparently pointless exchange was that in the event of a mobilisation the War Office intended to use the 3rd battalion of a regiment to provide reinforcements for the regular battalions, while if a regiment had a 4th battalion it would be mobilised as a whole unit. The older unit (1st Durham Fusiliers, then the 3rd battalion) wished to remain as a fighting unit, and so exchanged numbers. All volunteer battalions were renumbered to create a single sequential order.

First World War
The Durham Light Infantry would send 22 battalions to fight and lose 12006 other ranks during the course of the war. The regiment's territorial components formed duplicate second and third line battalions of progressively lower fitness men. Many battalions were formed as part of Secretary of State for War Lord Kitchener's appeal for an initial 100,000 men volunteers in 1914. They were referred to as the New Army or Kitchener's Army. The 18th and 20th Service battalions, were referred to as "Pals" because they were predominantly composed of work colleagues. The 19th battalion was originally a Bantam battalion.

Inter-War
By 1920, all of the regiment's war-raised battalions had disbanded, with the Territorial Force battalions were reformed in 1921, renamed the Territorial Army later in the year.

Second World War
The regiments's expansion during the Second World War was modest compared to 1914-18. Existing territorial battalions formed duplicates as in WWI (using whole rather than fractional numbers), while National Defence Companies were used to create a new "Home Defence" battalion. Hostilities only battalions were raised after the evacuation of Dunkirk. In addition to this, 26 battalions of the Home Guard were affiliated to the regiment, wearing its cap badge.

Post-World War II
In the immediate post-war period, the army was significantly reduced with all regiments being reduced to one battalion. The D.L.I. was one of only seven regiments to re-raise its second battalion in the early 1950s. After a long period of suspended animation the Militia battalions were finally disbanded in 1953.