Don Quixote

Don Quixote is Spanish writer Miguel de Cervantes's most famous novel, perhaps the most famous work of Spanish literature and a seminal work in modern Western writing.

It tells the story of a sadly deluded and idealistic nobleman who decides to set out on chivalric quests like the knights-errant of old. The adjective quixotic, and the phrase 'tilting at windmills' come to us from this book.

Quixote is the traditional spelling, but in modern Spanish it is rendered 'Quijote'.