Cide Hamete Benengeli is the Arab historian to whom the narrator attributes the story of Don Quixote. The book presents itself as a translation of his notebooks, found in Toledo, and the device gives the fiction the air of a document, plays with the idea of truth, and spreads authorship among several hands.
In chapter VIII of Part One, the narrator interrupts the duel with the Biscayan because the author of the story left the battle unfinished; in chapter IX he tells that he found in Toledo some notebooks written in Arabic, which a Morisco translated, and that the title was "History of Don Quixote de la Mancha, written by Cide Hamete Benengeli, Arab historian." The narrator becomes an editor who reads the translated historian and comments on him.
The joke lies in the irony. The narrator says that if any objection can be raised to the truth of the story, it can only be that its author was an Arab, since it is very characteristic of that nation to be liars. On the same page, he insists that the historian must be exact, truthful, and free of passion, and that history is the mother of truth. The book swears to be true and entrusts the truth to a presumed liar.
Cide Hamete reappears throughout the book, commenting and doubting: in chapter XXIV of Part Two he says he cannot persuade himself that everything told about the cave of Montesinos happened to the gentleman, and that if the adventure seems apocryphal, it is not his fault, and he writes it without declaring it false or true. In Part Two, Sancho changes his surname to Berenjena, which means eggplant, and the gentleman reminds him that the name is Moorish. At the end, it is he who closes the book and claims the character: for him only Don Quixote was born, and he for Don Quixote, against the fake writer from Tordesillas. The feigned translation protects the real author and, at the same time, separates him from the rival.