One of the most bizarre consequences of the English Civil War of 1642–46 was the celebrity status attained by a “dog-witch” named Boy, the loyal companion of Charles I’s nephew, Prince Rupert of the Rhine. Like his master, Boy was held to possess supernatural powers and gained popular interest through artistic renderings and sensational literature, where he was frequently portrayed as a devil or a witch. This compelling new book from Mark Stoyle sets out to uncover the true story of Boy—and in the process sheds new light on a fascinating series of collisions and interactions between polemic and traditional witch-belief in the troubled 1640s.