John lives in Greenock and is called with the "Eighteenth Royal" to fight in India. Jane asks him not to leave. He is killed by a French sword. His last words are "Greenock and sweet Bannockburn," as are hers when she heard the news of his death.
This song reminds McBride of "The Paisley Officer." It's a similar theme but "The Lad in the Scotch Brigade" is even closer: the war is different -- Egypt instead of India -- but it does share a line ("She threw her arms around him and cried, 'Do not leave me,'") and the girl's home "on the Banks of the Clyde." The British fought the French in India in the eighteenth century (source: "Rivalries in India: AD 1748-1760" in _History of the British Empire_, p. 4, at Historyworld site). - BS
This song is rather a curiosity. Greenock of course is in Scotland, and the girl lives by the Clyde, and who but a Scot would toast Bannockburn?
And yet, it's found in Ireland. And then there is the reference to the Eighteenth Royal.
It happens that the Eighteenth Foot was the Royal Irish Regiment , according to Ian S. Hallows, _Regiments and Corps of the British Army_, p. 319; it was disbanded in 1922 (when the Irish Free State was formed). (This unit should not be confused with the present Royal Irish Regiment, which is an Ulster unit. This is not to deny the distinction of the latter regiment; it's just not the same as the Eighteenth Foot.)
The site http://www.waterfordcountymuseum.org/exhibit/web/Display/article/31/2/?lang=en lists two occasions on which the Eighteenth served in Indian. The list of battle honours for the Eighteenth (found at http://www.regiments.org/regiments/uk/inf/018RIrish.htm) does not appear to include any Indian campaigns, but it did fight in Afghanistan, which is surely close enough. This unit did not fight the French at this time, of course, but it did serve in Madras, which had been the site of Anglo-French quarrels a century earlier.
So how did a seemingly-Irish regiment end up in a seemingly-Scots song? Don't ask me.... - RBW