In researching my family tree I have discovered that my great-great-great-great-grandfather Nicholas Sigon was based in Perth in 1797 as a member of the 23rd Regiment of Foot which subsequently became the Royal Welch Fusiliers.

Can anyone suggest where I might best research any papers remaining from that time to see what further information I can discover about him?

Many thanks in anticipation of any help which might be forthcoming.