It used to be "received wisdom" that songs that dealt more-or-less sympathetically with Napoleon must somehow be Irish, but this is to ignore political developments in Britain at that time. Certainly some are Irish at least in part (The Bonny Bunch of Roses was set specifically to an Irish tune) but others don't appear to be, and were if anything more popular in England and Scotland.

There is more work to be done on the whole subject, and the identity of George Brown (credited on some broadsides as writer of various songs, including The Bonny Bunch of Roses) is one question that I'd like to see answered. We won't be getting much reliable information from Frank Harte, though, it seems.