This Element explores the relation between historiography and testimony as a question about what it means to know and understand the past historically. In contrast with the recent rapprochement between memory accounts and history in historical theory, the Element argues for the importance of attending to conceptually distinct relations to past actions and events in historical thinking compared with testimony. The conceptual distinctiveness of history is elucidated by placing historical theory in dialogue with the epistemology of testimony and classical philosophy of history. By clarifying the rejection of testimony inherent in the evidential paradigm of modern historical research, this Element provides a thoroughgoing account of the ways in which historical knowledge and understanding relates to testimony. The argument is that the role of testimony in historiography is fundamentally shaped by the questioning-activity at the core of critical historical research. This title is also available as Open Access on Cambridge Core.