El ingenioso hidalgo Don Quijote de la Mancha is a classic Spanish novel by Miguel de Cervantes. It tells the story of Alonso Quijano, a man who becomes obsessed with chivalric books and decides to become a knight-errant named Don Quixote. Accompanied by his loyal squire Sancho Panza, he travels through Spain living imaginary adventures, often mistaking ordinary situations for heroic battles. The novel explores themes such as reality versus illusion, friendship, idealism, and human nature, and is considered one of the most important works in world literature.