During the Peninsular War, volunteers from Wellington's army led by militiaman Foyers storm Blucher's castle in Spain. Foyers is wounded. He asks a comrade to tell his father of his death, recalls his home life, then dies. All mourn him as he is buried.
To quote MacColl & Seeger, "The Duke of Wellington's investment of Marshal Marmont's French forces and the retreat which followed were not particularly bloody by modern standards -- a mere 10,000 or so died. Wellington gained an earldom and a Perthshire militiaman gained an epitaph which is still sung round the campfires of travelling people." Note that Blucher, an enemy of Napoleon, is here described as his ally. - PJS
That seems to be a peculiarity of the John MacDonald's version, though; neither Ford nor Ord have such a reference. Ford, who reports collecting the song c. 1870, reports a newspaper item listing John MacNeill as author.
Burgos, almost due north of Madrid and about two-thirds of the way from there to the ocean, is not one of the great cities of Spain, but it lies in a gap in the mountains and thus guards the most direct path between France and Madrid. As long as Napoleon's enemies held Burgos, most of Spain (except the Ebro valley and cities such as Zaragosa and Barcelona) were safe, and as long as France held it, she could operate armies in Spain freely.
Early in the Peninsular War, Napoleon directed several campaigns toward Burgos, and later on, it became one of the chief Coalition objectives. Capture Burgos, and the French garrisons in Spain would be cut off from reinforcements.
Wellington besieged Burgos in September and October of 1812, but -- despite the indirect implication of the song -- did *not* capture it; he abandoned the siege as a relief army approached. - RBW
Yates, Musical Traditions site _Voice of the People suite_ "Notes - Volume 8" - 1.3.03: "Some authorities cite one James MacNeil as a possible author for the song." - BS