Under threat of invasion by the French Revolutionary government from 1793, and with insufficient military forces to repulse such an attack, the British government under William Pitt the Younger decided in 1794 to increase the Militia and to form corps of volunteers for the defence of the country.

The Royal Warrant asked standing Yeomanry regiments to provide service companies of approximately 115 men each.

[3] The first contingent of recruits contained 550 officers, 10,371 men with 20 battalions and 4 companies,[4] which arrived in South Africa between February and April 1900.

It was organised in four squadrons and a machine gun section formed from South African war veterans to perpetuate 28th (Bedfordshire) Company, 4th Bn, Imperial Yeomanry.

[7] On 1 April 1908, the regiment was renamed as the Bedfordshire Yeomanry and transferred to the Territorial Force, trained and equipped as lancers.

[a] On 10 March 1918, it left the 1st Cavalry Division with the intention of converting it to a cyclist 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.

[14] The record of the unit's service was set out by L. R. C. Southern (Lieutenant), an officer of the regiment, in The Bedfordshire Yeomanry in the Great War (Rush & Warwick, Bedford, 1935).

It remained in the United Kingdom until July 1917 when it was absorbed into the 1st Reserve Cavalry Regiment at The Curragh.

Following the experience of the war, it was decided that only the fourteen most senior yeomanry regiments would be retained as horsed cavalry, with the rest being transferred to other roles.

[28] At the outbreak of the war, 148th (Bedfordshire Yeomanry) Field Regiment RA was assigned to the 18th (East Anglian) Infantry Division.

[33] The Bedfordshire Yeomanry has been awarded the following battle honours:[2] Somme 1916 '18, Flers-Courcelette, Cambrai 1917 '18, Amiens, Albert 1918, Hindenburg Line, St Quentin Canal, Beaurevoir, Pursuit to Mons, France and Flanders 1915–18 The Royal Artillery was present in nearly all battles and would have earned most of the honours awarded to cavalry and infantry regiments.

In 1833, William IV awarded the motto Ubique (meaning "everywhere") in place of all battle honours.

[34] Prior to 1914, the Bedfordshire Yeomanry wore a dark blue review order with white gorget collar, piping and trouser stripes.

The headdress was a blue peaked cap with white lancer style quartering.