(A). A Brummagem captain; a “General von Poffenburgh.” Michael Perez is so called in Rule a Wife and have a Wife, by Beaumont and Fletcher.
“To this copper-captain was confided the command of the troops.” —W. Irving.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
More on Copper Captain from Infoplease: