A second line battery, 2/1st Essex RHA, served on the Western Front in 1917 and 1918 as part of an Army Field Artillery Brigade.

[2] On 18 March 1908, Essex Royal Horse Artillery (Territorial Force) was proposed as a new unit and it was recognized by the Army Council on 7 July 1908.

[7] The battery was equipped with four[1] Ehrhardt 15-pounder[8] guns and allocated as artillery support to the Eastern Mounted Brigade.

2nd Line units performed the home defence role, although in fact most of these were also posted abroad in due course.

[9] The 1st Line battery was embodied with the Eastern Mounted Brigade on 4 August 1914 at the outbreak of the First World War.

The brigade concentrated in the Ipswich area of Suffolk and joined the 1st Mounted Division on formation on 5 August.

[12] In September 1915, the Eastern Mounted Brigade (without the battery) was dismounted and left Suffolk for Liverpool en route to Gallipoli.

[14] The battery, along with the Hampshire and West Riding RHA, joined V Lowland Brigade, Royal Field Artillery (T.F.)

[20][b] XX Brigade, RHA (with the Hampshire Battery) joined the Yeomanry Mounted Division at Khan Yunis on 5 July.

However, Essex Battery, RHA remained with 52nd (Lowland) Division until 17 September 1917[15] when it joined 7th Mounted Brigade which had returned to Egypt from Salonika on 29 June.

However, demobilization began immediately and most of the British war time units had left by the middle of 1919.

[26] The pre-war Territorial Force infantry divisions were generally[c] supported by four field artillery brigades.