The regiment, which traces a history back to 1794, was re-formed on the creation of the Territorial Force in April 1908. It was placed under orders of the Lowland Mounted Brigade.
Its headquarters and A Squadron were based in Ayr, B Squadron in Cumnock, C Squadron in Kilmarnock and D Squadron in Beith.
1/1st Ayrshire Yeomanry
13-27 June 1914: held its annual summer training camp, this year at Netherhall in Wilton Lodge Park at Hawick.
4 August 1914 : mobilised and soon moved to Cupar in Fife.
Late October 1914: moved to new hutted camp at Annsmuir.
2 September 1915: newspaper report that the brigade is under orders to proceed overseas. Departed camp 26 September. Moved by train to Devonport and boarded the ship “Arcadian”. Sailed at 6:30pm on 27 September. Going via Gibraltar and Malta, arrived at Mudros on 9 October. Trans-shipped onto HMS “Partridge”.
11 October 1915 : disembarked at W Beach (Lancashire Landing) at Cape Helles, Gallipoli. Brigade placed under orders of 52nd (Lowland) Division.
24 October 1915: main body went into trenches for first time.
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) Battalionn, the Royal Scots Fusiliers. Placed under orders of 229th Brigade in 74th (Yeomanry) Division.
Moved with the division to France.
21 June 1918 : moved to 94th Brigade in 31st Division.
2/1st
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.
3/1st
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.