This edited volume brings together work on the evidential systems of Tibetan languages. This includes diachronic research, synchronic description of systems in individual Tibetan varieties and papers addressing broader theoretical or typological questions. Evidentiality in Tibetan languages interacts with other features of modality, interactional context and speaker knowledge states in ways that provide important perspectives for typologists and our general understanding of evidential systems. This book provides the first sustained attempt to capture this complexity and diversity from both a synchronic and diachronic perspective.