Why did so many rulers throughout history risk converting to a new religion brought by outsiders? In his award-winning Unearthly Powers (2019), Alan Strathern set out a theoretical framework for understanding the relation between religion and political authority based on a distinction between two kinds of religion - immanentism and transcendentalism - and the different ways they made monarchy sacred. This ambitious and innovative companion volume tests and substantiates this theory using case studies from Kongo (1480–1530), Japan (1560–1614), Ayutthaya (Thailand, 1660–1690), and Hawaii (1800–1830). Through in-depth analysis of key turning points, Strathern demonstrates how theoretical arguments can be deployed to understand why warlords, chiefs and kings across the world did or did not convert to Christianity. Though this work examines a unique tapestry of characters and stories, these examples ultimately demonstrate that global patterns of conversion can be established to illuminate the religious geography of the world today.