This is a dishonest book--it pretends to be a scholarly history, with careful footnotes and a short bibliography, and all of the trappings of scholarly works, but in reality it's a piece of pure nonsense, eked out by a supposed letter from Captain Avery, and a fabricated story about Avery's friendship with Daniel Defoe, some smuggling and pirating, and a story in parts so sensational you'd swear it couldn't be true. Because it isn't.
Well, not all of it is fiction. Henry Every (or Avery) really did attack Aurangzeb's flagship and make off with a massive prize. He really did cause an international incident between Mughal India and the East India Company, to the point that open trade was seriously affected. Avery also vanished without being brought to trial, although the story of his laundering diamonds with some unscrupulous Bristol merchants, who fleeced him and left him penniless, is likely a story made up for "Charles Johnson's" General History of the Pyrates, which is the only place the story appears.
But so much else in this book is just plain wrong. Watch the footnotes carefully. When Kingsley and Cowan are describing Defoe's early business activities, they lean heavily on F. Bastian's 1981 book, The Early Life of Daniel Defoe--that's OK, although corroborating Bastian with information from either Paula Backscheider's or Max Novak's scholarly biographies would have been better. When they come to describe Defoe's friendship with Avery, there are no footnotes. Why? Because there's no evidence the two men ever even met. Kingsley and Cowan even slip out of historical narrative mode into something like cheesy romance novel mode, describing Defoe's actions and feelings, adding colourful little details here and there, as if signalling to the reader that they're in the realm of fiction.
Worse than that, though, are the outright lies. The authors claim, for example, that a 1712 play very loosely based on Avery, The Successful Pyrate, was actually a collaboration between Defoe and Avery, written under a pen name. That name? Charles Johnson, of course--the same name that would be used in 1724 as the author of General History of the Pyrates. They even flatly state that Charles Johnson the playwright is otherwise unknown, which is blatantly false: Johnson was fairly active in the early decades of the eighteenth century--several of his plays were performed and published, and we have records of his activities at Drury Lane Theatre. No one has ever doubted that The Successful Pyrate was written by the same person who wrote The Force of Friendship, and The Wife's Relief, and several other plays and afterpieces. Apart from The Successful Pyrate no one bothers to read his plays now; they weren't exactly blockbuster hits back then, either--but that doesn't mean Johnson himself didn't exist.
Earlier on, Kingsley and Cowan spend a lot of time discussing Samuel Annesley, the son of a famous clergyman who actually did know Defoe. Annesley junior was a rising star in the East India Company at the time of Avery's plundering of the Mughal ships, and had to deal with some of the fallout. There is one book on Annesley, written by Arnold Wright and published in 1918--and, of course, much of the information in this book derives from Wright. Except: Kingsley and Cowan dramatically state that Annesley mysteriously vanished in 1723, "never to be heard from again." Wright, however, flatly asserts that Annesley never disappeared, his life up to his death in 1734 is well documented, as is his last will. Wright even plainly decalres that the "mystery of Annesley's last days is no mystery," and he debunks the stories of Annesley somehow vanishing off a ship bound for England. Kingsley and Cowan intentionally deceive the reader, by placing an endnote reference to Wright's book--page 317--directly after a detailed description of the state of the "vanished" Annesley's cabin when it was finally opened. Except--a look at page 317 contains no such description, or even any mention of Annesley being on a ship, but it does contain some information about Annesley's request to his brother-in-law to help him out financially, which is included earlier in Kingsley and Cowan's paragraph. A reader who doesn't take the time to double-check the citations--and how many readers are going to do that?--can be easily duped into thinking Wright has endorsed their fictions. How much of this occurs throughout the text I have neither the time nor the desire to check, but I would imagine Kingsley and Cowan frequently play fast and loose with even their sources.
Either all of this is just extremely sloppy scholarship on Kinglsey and Cowan's part, in which case, you have to take what they say about this newly-discovered "Avery letter" with a grain of salt, or it's a deliberate attempt not to let facts get in the way of a good story, in which case you also have to take what they say about this newly-discovered "Avery letter" with a grain of salt. Whatever the reality is of this mysterious letter, upon which the whole book really depends, it's impossible to trust anything these authors say after so much flagrant fabrication and scholarly dishonesty.
There is a lot of excellent, first-rate pirate research out there, and we are beginning to understand much about both real pirate life and the fictions that have been around as long as the pirates themselves have been. This book, however, is dangerous to serious research, since, to use a phrase sometimes attributed to Samuel Johnson (erroneously!), "the book is both original and good; but what is good is not original, and what is original is not good."
And Defoe didn't write General History of the Pyrates, either. Let's put that one to bed forever.