Thanks to Teribus and Gutcher for what is undoubtedly more information directly relevant to "The Twa Recruiting Sergeants" than has ever appeared anywhere. This is Mudcat at optimal functionality, i.e. "its best."

Now for the contentious part.

Michie's "Deeside Tales," p.44, says that as a result of the punishment meted out to the 42nd in 1743, "though several recruiting paries were sent to the Highlands, not fifty men in the *subsequent five years* could be enlisted to supplement the ranks of the 43rd" in Flanders. (My emphasis.) Michie refers to the 1740s, not the '80s.

Ten men a year, in Michie's offhand estimate, suggests that a single recruiting visit to a single locale in the 1740s might have been lucky to snag even one or two. Thus, to say, as the song does, that "all" they enlisted was "forty and twa" is inconsistent with that era.   As Teribus and I have suggested, 42 is simply a pun on the 42nd Regiment (the Black Watch).

And at least *in the song*, 42 is assumed not to be very many: the song explicitly says that's why more men are being sought ("*Sae* list…and come awa'.") If that assumption relates at all to reality, it may support a very late date of composition when thirty or forty men really was a poor haul. But I'm only speculating. It may mean nothing at all.

I don't know much about the state of humor in old Aberdeenshire, but if I'd heard that a regiment called "The Forty-Twa" (rather than "The Forty-Second") was looking for men, I'd be very inclined to say "You mean there's only 42 in the whole bloody lot? They must be staying away in droves. The song need not refer specifically to the period Michie describes. The pun would have been possible at any time, and just *as a pun* it says nothing about when "The Twa Recruiting Sergeants" was written.

Who wrote the original lyrics, in our out of the army, is unknown. Moreover, Jeannie Robertson's song is unlikely to afford the unaltered original text. Pronouns may have been changed from the original, altering the writer's intended point of view.

Consider: If JR had sung "A' that *we* listit was forty and twa" instead of "they," the narrator would suddenly become one of the sergeants. In fact, it's tempting to guess that the original really did say "we," because it would make the appeal as unambiguous as that of 1706. It would also make the song rather less "wry" and thus, to some of us, less attractive.

But this thread chiefly concerns the song *as popularized by Jeannie Robertson and standardized by her fans.* There's no telling, in every detail, what the lyrics were like before, or what alterations, if any, she may have made over the years.   But in JR's version , the sergeants have to "catch" recruits rather than, say, "find" them. Sure, "catch" is there to rhyme with "Watch," but "catch" is all we have and, like it or not, that's what the song says. The song paints the sergeants as little more than official con men, though certainly their arguments might persuade some, and certainly some recruits would have been better off in the army than on the farm. That rhetorical "tension" is part of what makes the song interesting. (The jaunty tune helps too.) But unless I'm much mistaken, relatively few folkies hear the song as a respectful tribute to the personal opportunities offered by the British Army. The 1706 song, in contrast, is undeniably gung-ho and, unless written by a deluded civilian, undeniably mendacious.

As for the French, though Chesney's "Battle of Dorking" (1871) effectively began popular speculation that Germany would be Britain's next adversary, it wasn't until the papers reported the Entente Cordiale in 1904 that the average British subject might have breathed easy that France realistically was no longer a potential foe. Even if the government thought otherwise, the average late Victorian would not have been amazed to hear that the French were up to their old tricks. Old tricks were a French weakness, _non_?

But on the basis of the limited available evidence, it is certainly true that the entire song cannot antedate 1796 in any form or postdate (in form and substance) 1908. Not a very satisfying answer to the OP, but that's folklore for you.