It would be interesting to know where Gregg Butler got the song. There are probably mistakes in the transcription here ("stare" should be "snare", for instance, and of course the events took place in February-March 1811, not August) and I can't find any version from tradition that involves "saucy princes" or any other chorus come to that. Perhaps some modern intervention there?

Number 2182 in the Roud Folk Song Index, generally as The Battle of Barossa, with a few Scottish examples only listed at present; plus one from Sam Henry's Songs of the People, with the comment "This eagle [French standard, presumably] the first captured in the Peninsula, was taken by Sergeant Masterton of the 87th Royal Irish Fusiliers and is figured in the colours of the regiment." It seems that the song was sometimes sung to the tune of their regimental march.

Three broadside examples, all from Pitts of London, can be seen at Bodleian Library Broadside Ballads:

Battle of Barossa

No recorded examples of the song from English tradition, though it was evidently there, and Henry Burstow of Horsham listed it in his repertoire.