About which famous battle did the author of the book Sea Lord write a nonfiction book ? 
the battle of Waterloo
Title: Sea Lord (novel)
Passage: 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.  It was published by the Penguin Group.
Title: David Beatty, 1st Earl Beatty
Passage: Admiral of the Fleet David Richard Beatty, 1st Earl Beatty (17 January 1871 – 11 March 1936) was a Royal Navy officer.  After serving in the Mahdist War and then the response to the Boxer Rebellion, he commanded the 1st Battlecruiser Squadron at the Battle of Jutland in 1916, a tactically indecisive engagement after which his aggressive approach was contrasted with the caution of his commander Admiral Sir John Jellicoe.  He is remembered for his comment at Jutland that "There seems to be something wrong with our bloody ships today", after two of his ships exploded.  Later in the war he succeeded Jellicoe as Commander in Chief of the Grand Fleet, in which capacity he received the surrender of the German High Seas Fleet at the end of the war.  He then followed Jellicoe's path a second time, serving as First Sea Lord—a position that Beatty held longer (7 years 9 months) than any other First Sea Lord in history.  While First Sea Lord, he was involved in negotiating the Washington Naval Treaty of 1922 in which it was agreed that the United States, Britain and Japan should set their navies in a ratio of 5:5:3, with France and Italy maintaining smaller ratio fleets of 1.75 each.
Title: Bernard Cornwell
Passage: Bernard Cornwell, OBE (born 23 February 1944) is an English author of historical novels and a history of the Waterloo Campaign.  He is best known for his novels about Napoleonic Wars rifleman Richard Sharpe.  Cornwell has written historical novels primarily of English history in five series and one series of contemporary thriller novels.  A feature of his historical novels is an end note on how the novel matches or differs from history, for the re-telling, and what one might see at the modern site of the battles described in the novel.  One series of historical novels is set in the American Civil War.  He wrote a nonfiction book on the battle of Waterloo, in addition to the fictional story of the famous battle in the Sharpe Series.  Two of the historical novel series have been adapted for television; the Sharpe television series by ITV and "The Last Kingdom" by BBC.  He lives in the US with his wife.  He alternates between Cape Cod, Massachusetts and Charleston, South Carolina.
Bernard Cornwell Sea Lord (novel)