In 1912 the internationally known German historian Eduard Meyer published a book that ranked as a curiosity among his writings to that point. In it this remarkably prolific scholar, who in the previous thirty years had published a monumental five-volume history of the ancient world and 274 other books, treatises, and articles, explored two topics that were so alien to the mainstream of his previous work that it baffled his learned peers. Those topics were Mormonism and Islam. Entitled Ursprung und Geschichte der Mormonen, mit Exkursen uber die Anfange des Islams und des Christentums (The origin and history of the Mormons, with excurses on the beginnings of Islam and Christianity), it remains a curiosity even today. Besides being generally inaccessible (it is available only in a single, limited-edition English translation produced in 1961), almost nothing is known by most people today about its author and contents. Who was Eduard Meyer, and what prompted him to examine a nineteenth-century American religion and a seventh-century Mideastern one, both of which were chronologically far removed from his historical writings about the ancient world?