Aide-de-camp to the Duke of York in the disastrous campaign that was fought in Holland in the last year of the eighteenth century, and of which he has left an unforgettable description in his Narratives, Bunbury, unlike most British army officers of his time, took his profession seriously. He served as chief of staff in Sicily to a number of army commanders, and distinguished himself at the battle of Maida.

His reputation for sound administration won him the appointment in England of undersecretary of state for war, a post he held from 1809 until the war was finally over. It was in his retirement that Bunbury wrote his history of the Napoleonic wars as he had personally experienced them. But his writings also include vivid accounts of his travels in Sicily and France at various stages of his life.

Bunbury's writings, together with the story of his life, provide a fascinating and informative picture of the British army and many of its commanders during the Napoleonic wars, and of the exiled emperor Napoleon, as well as casting an interesting sidelight on the English political and economic scene in the first half of the nineteenth century.