Scholars of Vedic religion have long recognized the centrality of ritual categories to Indian thought. However, there has been little attempt to bring the same systematic rigor to later Hindu materials and to understand the broader systems that connect disparate forms of religious practice. Excavating the deep history of a prominent ritual category in "classical" Hindu texts, Geslani traces the emergence of a class of rituals known as santi, or appeasement. This ritual, intended to counteract ominous omens, developed from the intersection of the fourth Veda-the oft-neglected Atharvaveda-and the emergent tradition of astronomy-astrology. This development would come to have far reaching consequences on the ideal ritual life of the king in early-medieval Brahmanical society. The mantric transformations involved in this history led to the emergence of a politicized ritual culture that could encompass both traditional Vedic and newer Hindu performers and practices. From astrological appeasement to gift-giving, coronation, and image worship, Rites of the God-King chronicles the multiple lives and afterlives of a single ritual mode, unveiling the always-inventive work of the priesthood to imagine and enrich royal power. Along the way, Geslani reveals the surprising role of astrologers in Hindu history, elaborates upon concepts of sin and misfortune, and forges new connections between medieval texts and modern practices. In a work that details 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.