Miguel de Cervantes' 'Don Quixote,' published in two parts in 1605 and 1615, is widely considered the first modern novel and one of the most influential works of Western literature. It tells the story of an aging nobleman who loses his mind after reading too many chivalric romances and decides to become a knight-errant. Alongside his faithful squire, Sancho Panza, he embarks on a series of comedic and tragic adventures. The book is famous for 'tilting at windmills,' a phrase used to describe fighting imaginary enemies. Cervantes used the novel to satirize the outdated ideals of knighthood and to explore the nature of reality versus illusion. It was the first book to use a complex, self-referential narrative structure where the characters are aware that they are in a book. Its impact on the Spanish language is so profound that Spanish is often called 'la lengua de Cervantes.'