[1][2][3] On 7 May 1794 the Lord Lieutenant of Hertfordshire, the Marquess of Salisbury, called a meeting at Hertford that opened a subscription list to provide arms and uniforms, and resolved to raise a force of yeomanry that could be embodied in defence of the county.

All seven Troops were on parade at Hatfield Park (the Marquess of Salisbury's country house) when the Militia, Yeomanry and Volunteers of the county were reviewed by King George III on 13 June 1800.

[4][11] All the Volunteer Cavalry were disbanded after the Treaty of Amiens, but the peace was short-lived, and on the resumption of war the Hertfordshire units were reformed in August 1803 with an additional Troop, giving the county the following Yeomanry and Volunteer Cavalry by 1805:[4][2][8][12][13] On 20 August 1803 Sir Abraham Hume assumed command of the South Hertfordshire Legion, an all-arms 'battle group' consisting of the Southern Troop of Yeomanry Cavalry, the Horse Artillery Troop, and the Cheshunt and Wormley Volunteer Infantry, one of the infantry units that had been raised in the county.

Similarly, after the resignation of Capt George Villiers, his elder brother the Earl of Clarendon was promoted from Cornet to command in his place.

Arthur De Vere Capell, Viscount Malden, formerly of the Royal Horse Guards, who had been second-in-command, was promoted lt-col to command the South Herts regiment on 9 September 1864.

[5][6][7][18][22][23] Viscount Malden died in March 1879, and his second-in-command, Edward Villiers, 5th Earl of Clarendon, was promoted lt-col in command on 19 July 1879.

The Hertfordshire Yeomanry were assigned as 'divisional troops' to 2nd Division of I Corps based at Chelmsford, alongside Regular Army units of infantry, artillery and engineers stationed in Eastern England.

[7][24][26] Following a string of defeats during Black Week in early December 1899, the British government realised that it would need more troops than just the regular army to fight the Second Boer War.

[6][7][24][38][39] Among the civilian volunteers who joined the 42nd Company was Dr Arthur Martin-Leake from Hemel Hempstead District Hospital, who enlisted as a trooper.

After his year's service Martin-Leake became a medical officer in the South African Constabulary and won the Victoria Cross (VC) for rescuing wounded under fire in February 1902.

The Herts Yeomanry held squadron parades at Culford on 22 August where the officers and men were invited to volunteer, and more than 80 per cent of the regiment did so at once.

The regiment fought in the final Battle of Megiddo and then carried out an epic march up the coast of Ottoman Syria to liberate the ports.

[60][47][54][82] In mid-1915 the 3rd Line regiment took over the role of draft-finding for the 1/1st Herts Yeomanry overseas, and the remaining home service men were transferred to join a squadron to a Provisional Brigade.

The 2/1st left Hertford in June 1915 for two months' training on Epsom Downs, and then went to the Thetford–Brandon area to join 69th (2nd East Anglian) Division in First Army of Central Force, responsible for the defence of Eastern England.

The battalion was issued with steel helmets and trained for beach landings from naval destroyers, to wade ashore with their bicycles on their shoulders.

Upton, transferred to the Herts Yeomanry from the Eastern Mounted Bde's Transport and Supply Column of the Army Service Corps.

[89] Before the TF reformed on 7 February 1920 the War Office had decided that only a small number of mounted Yeomanry regiments would be required in future, and the remainder would have to be re-roled, mainly as artillery.

When 21st Army Group was formed in July 1943 to prepare for the Allied invasion of Normandy (Operation Overlord), 86th (HY) Fd Rgt was assigned to I Corps.

18th Division sailed on 31 October 1941 bound for Basra as reinforcements for Middle East Forces, but while it was at sea news arrived of the Japanese attacks on Pearl Harbor and Malaya.

Fighting with whatever guns were available until its own 25-pdrs arrived, 135th Field Rgt took part in the final stages of the disastrous Malayan campaign and the defence of Fortress Singapore.

[102][104][103][114] As prisoners of war (PoWs) many of the men of 135th Field Rgt were forced to work on the Wan Po viaduct on the Burma Railway, which inspired the book and film The Bridge on the River Kwai.

[108][116] 79th (Hertfordshire Yeomanry) Heavy Anti-Aircraft Regiment, Royal Artillery was formed in 1939 with headquarters at Watford.It served in the Battle of France, The Blitz, Operation Torch and the Italian Campaign before being placed in suspended animation in early 1945.

[120] At the time of the Royal Review in 1800, the five Yeomanry Troops wore blue coats with red cuffs and collars and buff waistcoats.

D (Cashio) Troop was dressed as heavy dragoons in a scarlet coatee with green facings and a white metal helmet with black plume.

[20][124] In the mid-1860s the distinction between the heavy and light troops of the regiment was abandoned, and all wore a new uniform with a single-breasted scarlet tunic and a white metal spiked Dragoon helmet bearing the hart badge.

[22][125][126] Upon conversion to Imperial Yeomanry in 1906 the regiment adopted the standard khaki IY uniform with scarlet collars and cuffs; ORs wore a Slouch hat with the left side turned up and secured with the hart badge on a red rosette.

[95] In 1795 at Theobald's Park, Lady Prescott presented her husband's Southern Troop of Yeomanry with a standard bearing the Coat of arms of Hertfordshire.

Mrs Ward, wife of the commanding officer, presented the Gilston Trp with a pair of guidons similar to Marchioness's: the royal cypher on one side surrounded by the wording 'Gilston Troop of Herts Yeomanry' and on the other the county arms of the hart crossing a stream.

This was red with a circle inscribed HERTS YEOMANRY' inside a union wreath of roses, thistles and shamrocks, with a crown above and the battle honour 'SOUTH AFRICA 1900–01' on a scroll beneath.

After 1924 the battle honours (South Africa and nine from World War I) appeared in two columns of scrolls, but it was never paraded after the regiment converted to artillery.