The actual date of the raising of the 20th Light Dragoons was 1791 when Lieutenant-Colonel Farington Gardner was issued a letter authorising him to raise the regiment. But there were two previous raisings that only lasted 4 years each. The first one was raised during the Seven Years War (1756 - 63). The eight British dragoon regiments were ordered to raise a light Troop each and these were brigaded together for the raid on St Malo in June 1758. The success of the Light Cavalry Brigade prompted the raising of separate Light Dragoon regiments.
20th (Inniskilling) Light Dragoons 1759 - 1763
There are two accounts of the origin of the 20th (Inniskilling) Light Dragoons. L B Oatts in Emperor's Chambermaids says that the town of Enniskillen raised the regiment as a contribution to the war effort. But Chichester and Burges Short in their Records and Badges of the British Army state that the regiment was raised from the Light Troop of the 6th Inniskilling Dragoons, and volunteers from other corps. The uniform was red coats with yellow facings but later changed to black facings. The regiment had 12 officers and 232 rank and file, organised into 4 Troops. It was commanded by Lieutenant-Colonel Sir James Caldwell Bt. The men were all Irish, there being no lack of recruits in Ireland. they did not go abroad but served in Ireland for the whole period of their existence until disbandment in 1763 when the Seven Years War ended.
20th Light Dragoons 1779 - 1783
The second incarnation of the 20th Light Dragoons occurred during the War of American Independence (1775-83) although the regiment remained in the UK. They were raised in 1779 at Bury St Edmunds from the Light Troops of the 3rd Dragoon Guards, 1st Royal Dragoons, 6th Inniskilling Dragoons, and the 11th Dragoons. They were employed on the coasts of East Anglia policing the operations of smugglers, or Free-traders as they were called. This made them rather unpopular but the job did not just prevent the influx of contraband but also made it difficult for French spies to enter the country. They were disbanded in 1783 when the Treaty of Versailles ended the war.