It was formed in Belgium in 1914 and served on the Western Front as part of the 3rd Cavalry Division.

The third regiment, the 1/1st Essex Yeomanry, did not join from the Eastern Mounted Brigade in England until 11 December.

[1] At other times, the brigade formed a dismounted unit and served in the trenches (as a regiment under the command of the brigadier).

The British and Canadian units remained in France[6] and most of them were transferred to the 3rd Cavalry Division causing it to be extensively reorganized.

[2] It appears to have been dissolved at this point as the constituent regiments (the Essex,[7] Leicestershire[8] and North Somerset Yeomanry[9]) were slated to be converted to cyclist units, G Battery, RHA was posted to XVII Brigade, RHA,[10] and 8th MG Squadron joined 7th Cavalry Brigade.