Sir John Keegan

Sir John Keegan (1934–2012) was an English military historian, lecturer, journalist, and author widely regarded as one of the foremost writers on the nature of warfare and combat. He taught military history at the Royal Military Academy Sandhurst for many years before becoming defense correspondent and later defense editor for The Daily Telegraph.

Clapham, London, England May 15, 1934 Wikipedia
military history nonfiction journalism