This volume is a comprehensive compilation of primary textual sources pertaining to the history of Hunnic peoples in the vast area encompassing Central and South Asia. Sources in nearly a dozen languages have been carefully selected by scholars with a specialisation in the particular language and relevant research experience. Each excerpt in the chrestomathy is presented in the original language, accompanied by an authoritative translation into a modern European language to make it accessible to specialists of other fields. Many texts are, moreover, accompanied by a commentary highlighting crucial points of interest, problematic issues and connections to the information revealed in other sources. The Sourcebook is the outcome of an interdisciplinary workshop held at Eötvös Loránd University (Budapest, Hungary) in August 2017, organised by the project Beyond Boundaries and funded by the European Research Council. The initial compilation of source texts was selectively presented, analysed and discussed at this workshop, culminating in the present volume, whose publication has also been supported by the ERC. The authors and the editor present the book to the community of scholars and enthusiasts in hopes that, by making pertinent primary sources accessible, it will serve as a solid foundation on which to base future research. The included commentaries are thus not intended to be exhaustive, but to instigate further enquiry. For in-depth discussion of many issues raised here, a Companion series is planned to follow the Sourcebook. The first companion volume, a study of the Alkhan by Hans Bakker, is released simultaneously by Barkhuis, Groningen.