Grandfather Darby Kelly "beat a drum so neat" for Marlboro at Blenheim and Ramilie. His father drummed "when great Wolf died." The singer was with Wellington in Portugal and when "He made Nap prance right out of France"
Broadside Bodleian Harding B 11(696) notes provide the following military references for the grandfather, father, and singer, respectively: "Marlborough, John Churchill, Duke of, 1650-1722; Wolfe, James, 1727-1759; Wellington, Arthur Wellesley, Duke of, 1769-1852" - BS
Given that the earliest possible date for this song is 1814 (when Napoleon abdicated for the first time), and a date after Waterloo (1815) is more likely, it seems clear that the broadsides cited are the original publication of the song in this form. Obviously, from the dates, Darby Kelly was a drummer boy, not an actual soldier, in the War of the Spanish Succession. Nonetheless, the range of dates would better suit four or five generations than three; one wonders if there wasn't an intermediate version, in which perhaps the grandson fought in the American Revolutionary War rather than the Napoleonic Wars. - RBW