Don Quixote de la Mancha.

Widely regarded as the world's first modern novel, Don Quixote chronicles the famous picaresque adventures of the noble knight-errant Don Quixote de La Mancha and his faithful squire, Sancho Panza, as they travel through sixteenth-century Spain. [Translated by John Ormsby.]

This book includes both parts.

The first part was originally published in 1605, see *El ingenioso hidalgo don Quijote de la Mancha*
The second part was published in 1615, see *Segunda parte del ingenioso caballero don Quijote de la Mancha*