Mirror of Knighthood
(The). One of the books in Don Quixote's library, a Spanish romance at one time very popular. Butler calls Hudibras “the Mirror of Knighthood” (book i. 15).
“The barber, taking another book, said, `This is the Mirror of Knighthood. ' ”- Part 1, book i. 6.1
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894