August 1914 : headquarters and “A” Squadron in Ayr, “B” Squadron in Cumnock, “C” Squadron in Kilmarnock, “D” Squadron in Beith. Under command of the Lowland Mounted Brigade.
September 1915 : moved as dismounted troops to Gallipoli.
11 October 1915 : attached to 52nd (Lowland) Division.
February 1916 : transferred to 1st Dismounted Brigade, which was broken up 16 October 1916. Regiment then moved to 2nd Dismounted Brigade.
January 1917 : with the Lanarkshire Yeomanry, formed 12th (Ayr and Lanark Yeomanry) Bn, the Royal Scots Fusiliers. Placed under orders of 229th Brigade in 74th (Yeomanry) Division.
21 June 1918 : moved to 94th Brigade in 31st Division.
Formed as a Second-Line regiment in September 1914, under command of 2/1st Lowland Mounted Brigade.
March 1916 : Brigade redesignated 20th Mounted Brigade.
July 1916 : converted into a Cyclist unit, in 13th Cyclist Brigade (which was redesignated 9th Cyclist Brigade in November 1916).
Remained in Scotland until moving to Ireland in May 1918, where it then remained.
Formed as a Third-Line training unit in 1915.
Remained in United Kingdom until disbanded in early 1917, when the personnel went to the 2/1st and to the 4th (Reserve) Bn, the Royal Scots Fusiliers.