August 1914: Mobilised. Based in Liverpool. Attached to the Welsh Border Mounted Brigade. Moved to Kent. October 1915: Regiment was split up. 29th October 1915: D Squadron left to join 30th Division, landing in France on 10th November, being briefly attached to 2nd Indian Cavalry division between 13th-26th April 1916. 14th November: C squadron attached to 35th Division and landed in France on 1st February 1916. 27th November 1915:Regimental Headquarters and B Squadron joined the 31st Division and by December had been sent to Egypt. March 1916: RHQ & B squadron was relocated to France, being briefly attached to the 2nd Indian Cavalry Division. May 1916: Regiment was reformed to form the VIII Corps Cavalry Regiment. July 1917: The Regiment was dismounted and sent to train as infantry. September 1917: Became a battalion of the King's, which was redesignated 18th (Lancashire Hussars Yeomanry) Battalion, the King's (Liverpool) Regiment.
22. Duke of Lancasters own Yeomanry
August 1914: Mobilised as part of the Welsh Border Mounted Brigade. September 1914: Regiment was then split up. A Squadron joined East Lancashire Division and was left for Egypt. By 29th January 1917, the squadron was made part of 53rd (Welsh) Division. On 23rd August, the squadron became part of XXI corps cavalry regiment and remained so in Palestine for the remainder of the war. April 1915: RHQ and C Squadron joined the 23rd Division, landing in France on 28th August 1915. Briefly attached to 1st Cavalry Division in late April to early May 1916. April 1915: D Squadron joined the 14th Division, landing in France 23rd May 1915. 14 May 1916: All the units (except A Squadron) reformed and together with 'C' Squadron the Surrey Yeomanry they formed III Corps Cavalry. 24 July 1917: They were dismounted and became G.H.Q troops. 24th September 1917: After infantry training, the regiment joined a battalion of the Manchester Regiment, which was redesignated 12th (Duke of Lancaster's Own Yeomanry) Bn, the Manchester Regiment.
23. Liecestershire Yeomanry
August 1914: Mobilised as part of North Midland Mounted Brigade. November 1914: Moved to France, joining the 3rd Cavalry Division. 1914: Saw service at the First Battle of Ypres. May 1915: At Second Ypres, the regiment gained battle honours for the Battle of St Julien and the Battle of Frezenberg, where a squadron of the regiment held the line for its entire brigade. 1916: After being heavily depleted in Second Ypres, the regiment did not see significant action throughout 1916. 1917: Saw action at the Battle of Arras and the Battle of the Scarpe. March 1918: Withdrawn from the division and ordered to reform as a cyclist battalion, later countermanded. 1918: Remounted and sent to the 3rd Cavalry Brigade of 2nd Cavalry Division, where it was split up to provide reinforcements. Saw action in the Battle of Amiens, the Battle of the Hindenburg Line, and the Pursuit to Mons, for each of which the regiment received a battle honour.
24. Lincolnshire Yeomanry
August 1914: Mobilised and formed a part of the North Midland Mounted Brigade. September 1914: Attached to the 1st Mounted Division. 1915: Ordered overseas and departed for Salonika but on route they received order to divert to Egypt. April 1916: Brigade was re designated as the 22nd Mounted Brigade and attached to the Western Frontier Force. Early 1917: Moved to the Anzac Mounted Division and participated in the Second Battle of Gaza. June 1917: Attached to the Yeomanry Mounted Division and were involved in the Third Battle of Gaza and the Battle of Beersheba. April 1918: The regiment left the brigade and their horses to become a dismounted unit of the Machine Gun Corps, merging with 1/1st East Riding of Yorkshire Yeomanry to form "D" Battalion, Machine Gun Corps. It was as the 102nd MGC that they moved to France in June 1918 and were attached to the First Army.
25. City of London Yeomanry (Rough Riders)
August 1914: Mobilised as part of the London Mounted Brigade. April 1915: Moved to Egypt. August: 1915: Dismounted and relocated to Gallipoli, where it fought in the Battle of Scimitar Hill. December 1915: Evacuated to Egypt and remounted. January 1916: Moved with Brigade onto Suez Canal defences. November 1916: Relocated to Salonika. June 1917: Returned to Egypt. Participated in the Allied advance into Ottoman-controlled Palestine. 7th April 1918: Removed from Brigade and reformed into E Battalion, Machine Gun Corps. 1st June 1918: Sent to serve in France. 17th August 1918: Renamed 103rd Battalion MGC.
26. 1st County of London Yeomanry
August 1914: Mobilised as part of the London Mounted Brigade. Joined 2nd Mounted Division at Streatley. April 1915: Division sent to Egypt. August 1915: Dismounted. Redeployed to Gallipoli. December 1915: Returned to Egypt and remounted. January 1916: Division broken up. Brigade moved to Suez Canal Defences and renamed 8th Mounted Brigade. November 1916: Brigade moved to Salonika. June 1917: Returned to Egypt. Brigade came under orders of Yeomanry Mounted Division (21 July). 24 April 1918: Division renamed 1st Mounted Division. 22 July 1918: Brigade renamed 11th Cavalry Brigade.
27. 2nd County of London Yeomanry
September 1914: moved to Egypt. 19 January 1915: placed under command of Yeomanry Mounted Brigade. August 1915: dismounted and moved to Gallipoli. Brigade placed under orders of 2nd Mounted Division and renamed 5th Mounted Brigade. December 1915: returned to Egypt and remounted. Left the Division. April 1916: under orders of 6th Mounted Brigade in Western Frontier Force. January 1917: splits up. RHQ and C squadron to Northern Suez Canal Defences; A Squadron to 53rd (Welsh) Division (14 Jan to 14 Feb) and then 74th (Yeomanry) Division (5 April to 23 August); B Squadron forms a depot at Zeitoun. August 1917: rejoined. Became XX Corps Cavalry Regiment. C Sqn remained at Zeitoun from July to September. April 1918: left the Corps and became "F" Battalion of the Machine Gun Corps. 1 June 1918: landed at Marseilles for service in France. 19 August 1918: renamed 104th Battalion MGC.
28. 3rd County of London Yeomanry
August 1914: moved with the brigade to Hounslow and then to join 2nd Mounted Division at Streatley. November 1914: moved with brigade to North Walsham. April 1915: moved to Egypt. August 1915: dismounted and moved to Gallipoli. December 1915: returned to Egypt and remounted. January 1916: Division broken up; brigade moved to Suez Canal Defences and renamed 8th Mounted Brigade. November 1916: moved to Salonika. June 1917: returned to Egypt; brigade under orders of Yeomanry Mounted Division (21 July). 24 April 1918: division renamed 1st Mounted Division. 22 July 1918: brigade renamed 11th Cavalry Brigade.