The Chan monk Qisong (1007-1072), an important figure in Northern Song religious and intellectual history, has garnered relatively little scholarly attention. This book provides a detailed biography with a focus on the influential historical writings he composed to defend Chan claims of a "mind-to-mind transmission" tracing back to the historical Buddha. It places his defense of lineage in the context not only of attacks by the rival Tiantai school but also of the larger backdrop of the development of lineage and patriarchs as sources of authority in Chinese Buddhism. It advances new arguments about these Chinese Buddhist innovations, challenges common assumptions about Chan masters, and offers insights into the interactions of Buddhists, Confucians, and the imperial court during the Song.