The 17th century book The Ingenious Gentleman Don Quixote of La Mancha tells of the supremely fanatical Don Quixote and his trusty sidekick, Sancho.

In the book, the protagonist, while on his journey, comes across giant windmills. Mistaking them for giants, Quixote lowers his lance and charges at one of them. It takes Sancho to show his master that the windmills were not evil, but instead were used for generating food and energy.