In 1770 Light Companies were added to infantry regiments. The Light Company and Grenadier Company were referred to as flank companies, taking their place on parade on the left and right of the line, respectively. Various styles of Light Infantry cap were worn in the infantry but this front and back view of a leather example has a thistle device which indicates that it could have been worn in the 1st Royal Regiment, although it is not certain.
Standing Orders for 9 May 1782: ‘Light Company - Jackets with wings and bugle horns on the straps and skirts, red waistcoat with lace, leather cap with green feather and rosettes, number 1 in front, the rest the same as battalion officers.’