1/1st

August 1914 : in Warwick. Part of the 1st South Midland Mounted Brigade, attached to 1st Mounted Division.

Moved with Brigade to 2nd Mounted Division in August 1914, and moved with them to Egypt, landing at Alexandria on 24 April 1915.

Landed at "A" Beach, Suvla Bay on Gallipoli, 18 August 1915. Took part in attack on Hill 112 on 21 August, advancing over 2 miles under heavy shrapnel fire.

Severe sickness, together with casualties, resulted in temporary reorganisation together with 1/1 Gloucestershire and 1/1/ Worcestershire Yeomanry, to form 1st South Midland Regiment, 1st Composite Mounted Brigade, in early September 1915. By the end of that month, only 41 men of original 308 men who had landed at Suvla Bay remained at duty.

Continued in trench warfare activities in Green Hill and Chocolate Hill sectors until evacuated to Mudros on 31 October 1915.

In total, 15 men were killed on Gallipoli and 94 wounded.

Moved with Brigade, which was then redesignated 5th Mounted Brigade, to Imperial Mounted Division in February 1917 (this was redesignated as Australian Mounted Division in June 1917).

The Regiment took part in many actions in the Palestine campaign with the Division, part of the Desert Mounted Corps.

In April 1918, left the Brigade as dismounted troops, and formed (with the South Notts Hussars) "B" Battalion, the Machine Gun Corps. Suffered loss of 93 men when transport ship taking unit from Egypt to Italy was torpedoed on 27 May 1918. Eventually landed in Italy on 21 June 1918 and moved to France where Battalion became 100th Bn, MGC.

2/1st

Formed September 1914, and remained in UK. Initially attached to 2/1st Mounted Brigade, which was attached to to 2/2nd Mounted Division in June 1915. In March 1916, Brigade was redesignated 10th Mounted Brigade, in 3rd Mounted Division. Four months later, the Division was redesignated 1st Mounted Division, and the Regiment moved to 1st Mounted Brigade. Became a Cyclist unit in September 1917, attached to 71st Division.

3/1st

Formed in June 1915. Remained in United Kingdom until affiliated into 4th Reserve Cavalry Regiment in early 1917.