Most accounts of Hinduism posit a radical difference between the aniconic fire sacrifice (yajña) and temple-based image worship (pūjā). The historical distinction between ancient Vedism and medieval Hinduism is often premised on this basic ritual opposition. Through an exacting study of ritual manuals, Rites of the God-King offers an alternative account of the formation of mainstream Hindu ritual through the history of śānti, or “appeasement,” a form of aspersion or bathing, developed in order to counteract inauspicious omens. This ritual, which originated at the nexus of the fourth and somewhat marginal Veda (Atharvaveda) and the emergent tradition of astronomy-astrology (Jyotiḥśāstra), would come to have far-reaching consequences on the ideal ritual life of the king in early medieval Brahmanical society—and on the ideal ritual life of images. The mantric substitutions involved in this history helped to produce a politicized ritual culture that could encompass both traditional Vedic and newer Hindu practices and performers. From astrological appeasement to gifting, coronation, and image worship, the author chronicles the multiple lives and afterlives of a single ritual mode, disclosing the always inventive work of priesthood to imagine and enrich royal power. Along the way, he reveals the surprising role of astrologers in Hindu history, elaborates concepts of sin and misfortune, and forges new connections between medieval texts and modern practice. Detailing forms of ritual that were dispersed widely across Asia, he concludes with a reflection on the nature of orthopraxy, ritual change, and the problem of presence in the Hindu tradition.