This is the first book-length biography of John Thomas North (1842-1896), known as ‘Colonel North’ in Britain and throughout the world as ‘The Nitrate King’. Using sources in Britain and Chile, the book traces North’s spectacular life from mechanic in Leeds, through thirteen years in Peru and Chile, to become one of the richest and best-known men of his generation, and the first Honorary Freeman of Leeds. North is today almost completely forgotten in Britain, and remembered in Chile only to be vilified as the archetypal predatory capitalist. The book calls for a revaluation, and examines several controversies—principally the enduring allegations that North helped manipulate the War of the Pacific, and was active in triggering the Chilean Civil War of 1891. The book describes North’s business investments; his re-invention as country gentleman at Avery Hill mansion; and his generosity, including the gift of Kirkstall Abbey to the city of Leeds.