About which famous battle did the author of the book Sea Lord write a nonfiction book ? 
Sea Lord (novel): Sea Lord (a.k.a. Killer's Wake in the United States) is a 1989 thriller novel by the British author Bernard Cornwell, one of a series of sailing-based thrillers. Bernard Cornwell:  He wrote a nonfiction book on the battle of Waterloo, in addition to the fictional story of the famous battle in the Sharpe Series.
the battle of Waterloo