August 1914: headquarters at 9 Dix’s Field in Exeter; “A” Squadron at Thorverton; “B” at Ottery St Mary; “C” atTotnes; “D” at Bodmin. Under command of the 2nd South Western Mounted Brigade.
October 1915 : dismounted and moved to Gallipoli. Withdrew back to Egypt in December 1915.
February 1916 : Brigade was absorbed into 2nd Dismounted Brigade.
4 January 1917 : merged with 1/1st North Devon Yeomanry to form the 16th (Royal 1st Devon and North Devon Yeomanry) Bn, the Devonshire Regiment and came under orders of 229th Brigade in 74th (Yeomanry) Division. Moved to France, landing at Marseilles 7 May 1918.
Formed as a Second-Line regiment in September 1914 and remained in UK until in November 1916, converted into a Cyclist unit and redesignated 4th Yeomanry Cyclist Regiment. Resumed original identity in March 1917. Moved to Ireland in May 1918.
Formed as a Third-Line training unit in 1915.
Remained in United Kingdom until disbanded in early 1917.