Nietzsche was an avid reader of Emerson's essays, and their influence is discernible from his earliest philosophical writings through to his final philosophical works. Nietzsche's copies of Emerson's books are covered with traces of his reading, from underlinings, exclamation marks, question marks, and dog-eared pages to numerous annotations and philosophical comments written in the margins. I use some of these to analyze the influence Emerson exerted on Nietzsche's conception of history and historiography. The two authors can be considered “twin souls” in that they both praised the strengthening effects of past greatness and, at the same time, opposed psychological subjugation or fanaticism. Nevertheless, they were not twin minds: Nietzsche rejected Emerson's metaphysical concept of an Oversoul and turned it into the ideal of a Dionysian soul, which aims at reliving the history of humanity in order to increase its power.