A major character of The Lord of the Rings was invented on the spot

Faramir is an important character in the novel The Lord of the Rings written by J. R. R. Tolkien. His creator had not planned him in the plot and imagined him at the very moment of making him cross the path of the heroes. This literary improvisation recounted by Christopher Tolkien forced the author to postpone the end of the book and to develop the history of Gondor.