1/1st

Newly raised in August 1914, initially by the Glamorgan County Association; later transferred to Montgomeryshire.

From early 1915, attached to 1/1st North Midland Mounted Brigade, attached to 1st Mounted Division. Soon transferred to 1/1st Eastern Mounted Brigade in same Division.

In September 1915, became dismounted and moved to ANZAC bridgehead on Gallipoli, landing there on 8 October 1915. Attached to 54th (East Anglian) Division, for work on mining operations at Hill 60.

Evacuated from Gallipoli on 15-20 December 1915, and moved to Egypt.

Moved with Brigade into 3rd Dismounted Brigade on Suez Canal defences, 22 February 1916. July 1916 moved to Western Frontier Force.

4 March 1917: merged with 1/1st Montgomeryshire Yeomanry to form 25th Bn, the Royal Welsh Fusiliers, part of 231st Brigade, 74th Division. Moved to the Western Front in May 1918.

2/1st

Formed September 1914, and remained in UK. Attached to 2/1st South Wales Mounted Brigade, which in September 1915 became attached to the new 1st Mounted Division. Absorbed by the 2/1st Montgomeryshire Yeomanry during 1916.

3/1st

Formed in 1915. Remained in United Kingdom until disbanded in early 1917.