In 1793, the French revolutionary government declared war on Great Britain, adding fear of foreign invasion to that of domestic insurrection and leading to real panic in London.
In place there was a complicated system of; Militia and Fencibles, raised to keep order in Britain & Ireland, alongside Home Service Battalions of regular army for service in the UK only, as well as Garrison and Invalids regiments (Pensioner out patients). Invalid battalions were part of the structure of the Royal Hospital Chelsea, the famous red-coated pensioners we see today were in-patients, needing care, the out patients were formed into battalions, in order to qualify for their pension the had to perform limited garrison duties.
The main military reserve, the militia, was considered neither effective nor trustworthy. It had been demobilised at the conclusion of the American Revolutionary War in 1783, and in the intervening decade it had been subject to cost-cutting measures that had left it deficient. Further fears of internal insurrection were not satisfied as the militia recruited from the working class, including the newly expanding industrial areas. The militia was the responsibility of each county’s Lord Lieutenant, for training and organisation but funding was from the central Government. This created different county levels and was open to widespread nepotism, especially as officer’s commissions could be bought and sold for advancement.
Service in the militia was by ballot, for men between 18 to 50 in a Parish. Avoiding the ballot, which was a compulsory service, could be made by Substitution for another man, or by paying a £10 fine (Approximately; £850 or 30 days wages today). As They were not volunteers, and served full time, they were moved so they would not serve in the county in which they were raised. They were often stationed in strategic points around the country, to relieve the regular army for overseas service.
Considering that there was not enough time to address the militia's deficiencies, the government turned again to volunteers to bolster the nation's defences in 1794.
Many Yeomanry units were raised as Troops at a wealthy landowners expense, some were manned by young aristocrats and voted in new members, much like a club. Others were entirely paid for by a single landowner who would appoint his workers as other ranks, such as Lulworth Castle estate, here the system allowed the employer to have both a military and civil hierarchy over his employees, but allowed for additional pay and time off from the job, for military training, including a “camp”. Skilled Farm workers were part of an emerging middle class, especially head gardeners and foremen on country estates. In some cases that meant they were entirety filled with the gentry and entry was voted in, like a club.
The appeal for volunteers led to the creation of the Volunteer Corps, of which the “Gentlemen and Yeomanry Cavalry”, as it was then called, was the mounted component of this force.
Often the yeomanry were seconded to Home Office departments, for example customs, to prevent smuggling or the magistrates to put down rioting.
Unlike the Volunteers and Milita the regular army, cavalry regiments did not recruit from the Yeomanry, meaning that few individuals saw foreign service (until the Boer War). However one Regiment was caught up in the last invasion of mainland Britain, the Battle of Fishguard.