Many thanks Biggles, the dates came about from a medical discharge certificate for my 2XGGF who was discharged from the 84th in 1811 with asthma and bad eyesight. In view of what you say about the fevers I would guess he was pleased to go. Now a more difficult one, I realise it is outside of the parameters you quote and if you cannot help I understand, but do you know which regiments were stationed at York and possibly other military establishments in the vicinity of York during 1776 please?