1/1st
August 1914 : headquarters and “A” Squadron at 17 Sir Isaac’s Walk in Colchester; “B” Squadron in Braintree;”C” in Waltham Abbey; “D” in Southend on Sea. Under command of the Eastern Mounted Brigade.
November 1914 : left the Brigade and moved independently to France, where it joined the 8th Cavalry Brigade in 3rd Cavalry Division.
March 1918 : a plan to convert the Regiment to a Cyclist unit was dropped in favour of making it into a machine-gun battalion, together with troops from the Bedfordshire Yeomanry. However within days this plan was also dropped and the regiment remounted and joined the 1st Cavalry Division.
April 1918 : Regiment split up, with one Squadron going to each other Regiment of the 1st Cavalry Division.
2/1st
Formed in September 1914 as a Second-Line unit and remained in UK until in September 1917, when converted into a Cyclist unit. Moved to Ireland in early 1918.
3/1st
Formed as a Third-Line training unit in 1915.
Remained in United Kingdom until disbanded in early 1917.