Miguel de Cervantes

His magnum opus, 

Don Quixote, considered to be the first modern European novel, is a classic of Western literature, and is regarded amongst the best works of fiction ever written.

Don Quixote follows the adventures of Alonso Quixano, an hidalgo who reads so many chivalric novels that he loses his sanity and decides to set out to revive chivalry, undo wrongs, and bring justice to the world, under the name "Don Quixote."