When hostilities commenced in 1914, there were 57 Yeomanry regiments in the British army:
1. Ayrshire Yeomanry
August 1914: Mobilised for war. Kept in UK on home defence duties. Sept 1915: Dismounted and regraded to infantry and deployed overseas, taking part in the landings at Gallipoli. October 1915: Attached to the 52nd (Lowland) Division. January 1916: Withdrawn and moved to Egypt. Early 1917: Amalgamated with The Lanarkshire Yeomanry to form the 12th (Ayr and Lanark Yeomanry) Battalion of the Royal Scots Fusiliers in 74th (Yeomanry) Division (The Broken Spurs), seeing service in the Palestine campaign. May 1918: Moved to the Western Front.
2. Bedfordshire Yeomanry
August 1914: Mobilised. Stationed at Hatfield Peverel and Stansted June 1915: Joined the 9th Cavalry Brigade, 1st Cavalry Division in France, eventually dismounting to serve in the Battle of the Somme, Battle of Cambrai and the Hundred Days Offensive in 1918. March 1918: Left the 1st Cavalry Division with the intention of converting it to a cylist unit, then to form a machine gun battalion with the Essex Yeomanry. The German Spring Offensive changed these plans and the regiment was re-mounted and returned to the 1st Cavalry Division. There it was split up, sending a squadron to each of the regiments in 9th Cavalry Brigade (8th, 15th and 19th Hussars). 2nd & 3rd lines of the regt remained in reserve in the UK until they were absorbed into other formations.
3. Berkshire Yeomanry
Info to follow.
4. Buckinghamshire Yeomanry
August 1914: Mobilised. Attached to the 2nd South Midland Mounted Brigade. September 1914: Transferred to the 2nd Mounted Division and moved with them to Egypt. August 1915: Dismounted and sent to Gallipoli. December 1915: Returned to Egypt and in 1916 they and the Brigade became an independent command and were redesignated as the 6th Mounted Brigade. February 1917: Brigade joined the Imperial Mounted Division. June 1917: Moved to the Yeomanry Mounted Division. April 1918: Amalgamated with the Berkshire Yeomanry, to form C Battalion, the Machine Gun Corps.This new Battalion moved to France in June 1918. They were then renumbered as 101 Battalion, the Machine Gun Corps.
5. Cheshire Yeomanry
1914–15: Underwent training in Norfolk. 1916: Sent to fight dismounted in Egypt. February 1916: After the battle of Mersa Matruh, the Duke of Westminster and the Cheshires mounted a raid against the Senussi using armoured cars. Driving across the desert at high speed, the Duke and his 12 cars caught the fleeing enemy, killing many of the Senussi and all of their Turkish companions, returning with three captured artillery pieces, nine machine guns and 30 prisoners. March 1916: The Rolls Royce-mounted Cheshire Yeomanry rescued the survivors of two British merchant ships, HMT Moorina and HMS Tara, which had been torpedoed off the coast of what is now Libya, earning the Duke of Westminster worldwide praise and the DSO. 1917: Palestine. Redesignated as a half battalion of the 10th King's Shropshire Light Infantry and saw fierce fighting against the Turks in battles for Jerusalem, Jericho and Tel Azur. April 1918: France. The KSLI saw action at the Somme, Bapaume and Epehy, suffering heavy casualties. June 1919: Battalion disbanded. March 1920: Cheshire Yeomanry was reconstituted as a cavalry regiment.
6. Denbighshire Yeomanry
September 1914: Became part the 1st Mounted Division. November 1915 : became a dismounted unit and moved to Egypt, forming part of the 4th Dismounted Brigade. February 1917: Re-roled as infantry to become the 24th (Denbighshire Yeomanry) Battalion, Royal Welsh Fusiliers, attached to the 231st Brigade, 74th (Yeomanry) Division. As part of the 74th (Yeomanry) Division, they were involved in the Second Battle of Gaza, Third Battle of Gaza, Battle of Beersheba and the Battle of Epehy.
7. Derbyshire Yeomanry
August 1914: Mobilised as part of Nottinghamshire and Derbyshire Mounted Brigade, but remained in England. 1915: Moved to Egypt with the 7th Mounted Brigade, 2nd Mounted Division. Sailed for Gallipoli, seeing action at the Battle of Scimitar Hill, serving as dismounted infantry. December 1915: Egypt. Employed with the Western Frontier Force in the Senussi Campaign. Februrary 1916: Salonika. March to June 1916: One squadron served with the 27th Division, whilst the regiment remained as GHQ reserve in Macedonia until the end of the war. September 1914: The regiment raised a second-line battalion, the 2/1st Derbyshire Yeomanry; this remained in the United Kingdom as part of 9th Mounted Brigade, 2/2nd Mounted Division, did not see service, and was converted into a cyclist unit in 1916.
8. Royal 1st Devon Yeomanry
4 August 1914: Mobilised and, with its brigade, moved to the Colchester area. September 1915: Dismounted. September 1915: Left Colchester for Liverpool. 9 October: Landed in Gallipoli and was attached to the 11th (Northern) Division (digging trenches). November 1915: Attached to the 2nd Mounted Division and 53rd (Welsh) Infantry Division. 19 December 1915: Evacuated to Imbros. December 1915: Landed in Alexandria to help defend Egypt. February 1916: 2nd South Western Mounted Brigade was absorbed into the 2nd Dismounted Brigade. It served on Suez Canal defences and as part of the Western Frontier Force. 4 January 1917: Amalgamated with the 1/1st Royal North Devon Yeomanry at Moascar, Egypt to form the 16th (Royal 1st Devon and Royal North Devon Yeomanry) Battalion, Devonshire Regiment in the 74th (Yeomanry) Division. 1917-18: Took part in the invasion of Palestine. It fought in the 2nd and 3rd Battles of Gaza (including the capture of Beersheba). Late 1917: Took part in the capture and defence of Jerusalem. March 1918: Battle of Tell 'Asur. 7 May 1918: Served in France and Flanders with the 74th (Yeomanry) division for the rest of the war. Took part in the Hundred Days Offensive including the Second Battle of Bapaume and the Battle of Épehy. October and November 1918: Took part in the Final Advance in Artois and Flanders.
9. Royal North Devon Yeomanry
4 August 1914: Mobilised and, with its brigade, moved to the Colchester area. September 1915: Dismounted. 9 October: Landed in Gallipoli and was attached to the 11th (Northern) Division (digging trenches). 19 December: Evacuated to Imbros. 30 December 1915: Landed in Alexandria to help defend Egypt. February 1916: Served on Suez Canal defences and as part of the Western Frontier Force. 4 January 1917: Amalgamated with the 1/1st Royal 1st Devon Yeomanry to form the 16th (Royal 1st Devon and Royal North Devon Yeomanry) Battalion, Devonshire Regiment in the 74th (Yeomanry) Division. 1917-18: With the 74th Division, it took part in the invasion of Palestine. It fought in the 2nd and 3rd Battles of Gaza (including the capture of Beersheba). Late 1917: Took part in the capture and defence of Jerusalem. March 1918: Battle of Tell 'Asur. 7 May 1918: Landed at Marseilles, France with 74th (Yeomanry) Division. It served in France and Flanders with the division for the rest of the war. It took part in the Second Battle of Bapaume and the Battle of Épehy. October and November 1918:Took part in the Final Advance in Artois and Flanders.
10. Dorset Yeomanry
August 1914: The 1/1st Queen's Own Dorset Yeomanry was mobilised. 1915: Deployed overseas to Egypt, then onwards to participate in the Dardanelles campaign, where they served as dismounted troops and were involved in the Battle of Gallipoli, the Battle of Sari Bair and the Battle of Scimitar Hill. January 1916: Returned to Egypt and became part of the 6th Mounted Brigade. February 1916: Battle of Aqqaqia. At this battle, the retreating Senussi were attacked by the Dorset Yeomanry with drawn swords across open ground. Under fire, the Yeomanry lost half their horses, and about a third of their men and officers were casualties (58 of the 184 who took part). Colonel Soutar, leading the regiment in this charge, had his horse shot from under him and was knocked unconscious. When he came to, he found himself alone amongst a group of the enemy. He drew his revolver, shot several, and took the Turkish leader Jaffir Pasha prisoner. February 1917: Took part in the 1st and 2nd Battles of Gaza, they later transferred to the Yeomanry Mounted Division. June 1917: Third Battle of Gaza and the Battle of Beersheba. July 1918: The Division was redesignated the 4th Cavalry Division. The Regiment remained with them in Palestine until the end of the war.