The same song-is alledged to have come from Somerset/Devon area, but no mention of regiment or where sent to fight. "It's true my love has listed and he wears a blue cockade" etc. Sung by Show of Hands, but I had heard it a long time ago in the Kent area sung by a local old chap in a folk club down there. Bill sables reckons it's a northern song. Many of these songs travelled up and down, undergoing transformations to fit the requirements of the singer. Can't help you much, but suspect it's Napoleonic wars.

Oxford Eng Dict-Cockade, a rosette etc worn in a hat as a badge of office-theword of French derivation.