Castlemartin
1/1st
August 1914 : in Tenby. Part of the South Wales Mounted Brigade, which joined 1st Mounted Division.
November 1915 : dismounted and moved to Egypt, landing March 1916. Brigade absorbed into 4th Dismounted Brigade.
2 February 1917: converted into the 24th (Pembroke and Glamorgan Yeomanry) Bn, the Welsh Regiment, and joined 231st Brigade, 74th Division.
2/1st
Formed September 1914, and remained in United Kingdom throughout the war. July 1916, converted into a Cyclist unit.
3/1st
Formed in 1915. Remained in United Kingdom until disbanded in early 1917.