It was indeed Sir Arthur Wellesley, later the Duke of Wellington, who infamously described his common soldiers with this harsh insult.
Historical records however show a more complex context: The Duke was reacting to severe breakdowns in military discipline among his soldiers looting, pillaging and worse after a battle or while still on campaign!
This particular figure of the Duke is based on a photograph of actor Hugh Fraser who played the noble lord in the 'Sharpe' television series. At the last London December show I was fortunate to meet and talk with Hugh and obtain the photo the figure is based on.