The successful transmission of Buddhism across geographical and cultural boundaries is one of the most interesting aspects of the historical study of Buddhism. If very few scholars have attempted any kind of general overview of this subject, this is no doubt due to the difficulty of writing a systematic account of what is not a single historical phenomenon, but a complex web of interactions, appropriations and adaptations. To be convincing, an account of the transmission of Buddhism ought to involve sources in several different languages, archaeological data from a range of geographically disparate areas, an understanding of the function of trade routes and hubs, and the socio-political background to the development of new Buddhist communities. Moreover, a sophisticated account of the transmission of Buddhism must be prepared to face questions about the concept of “transmission” itself, which while useful in denoting the general scope of the project, can lead to overly simplistic views of monolithic traditions being carried across cultural boundaries by valiant individuals.

Which is all to say that Jason Neelis's new study of the transmission of Buddhism within and beyond South Asia is very welcome. The primary reference point for Neelis's discussion of the nature of the transmission of Buddhism is Erik Zürcher, whose work from the 1950s to the 1990s represents the most sustained reflection on this subject. Examining the gradual development of Buddhism in China, and the quite different, later, development of Buddhist institutions in the city-states on the trade routes between South Asia and China, in his later work Zürcher concluded that the initial impact of Buddhism in China was due to “long-distance transmission” rather than “contact expansion”. Though his work has been the subject of subsequent criticism, in distinguishing these two forms of transmission Zürcher initiated an important theoretical framework for the study of the transmission of Buddhism.

In the introduction to this book, Neelis carefully describes Zürcher's ideas about transmission. Neelis also draws on more recent theoretical work on the movement of religions, settling, for his own analysis, on a “networks approach”, the “mapping of conduits between nodes for the localization of religious, economic and political power” (p. 12). Neelis identifies the key motivating factor in the establishment of new Buddhist hubs (through the construction of monasteries and stupas) in the “economies of merit”, in which the monastic institution is dependent on the merit-making acts of lay donors, and these donative acts are dependent on the ideological framework of religious merit.

While Zürcher's most important work, The Buddhist Conquest of China (1959) viewed the transmission of Buddhism from South Asia to China from the perspective of China, the main part of Neelis's book concerns the transmission of Buddhism within South Asia and from there to the “Northwestern borderlands” such as Gandhārā and Uḍḍiyāna. Much of the book is syncretic, in that it is a careful assembling and ordering of previous work in history, archaeology and epigraphy. This in itself is a formidable achievement, though the sheer accumulation of detail can at times be difficult to assimilate. In essence, Neelis provides an unparalleled description of the historical context and the social conditions that allowed Buddhist institutions to flourish and spread in these regions.

The care with which the chapters on South Asia have been constructed is evident in the range of sources, and the use, wherever possible, of the most recent available research. The subequent chapter on the transmission of Buddhism along the “Silk Routes” of eastern Central Asia is briefer than those before it, and relies more on other synopses of this topic by authors such as Xinru Liu and Marilyn Rhie. This is a pity because it is in this territory that Neelis meets Zürcher; yet because this chapter is largely a recapitulation of other works, Zürcher's later theories of long-distance transmission and contact expansion are in the end reiterated rather than challenged or refined.

Yet this is a minor criticism, itself countered by the title of the book, which places the locus of its study as the north-western borderlands. As such, the book provides not only a wealth of up-to-date research to contextualize the transmission of Buddhism, but also a subtle and light-touch theoretical framework which emphasizes relational networks and multi-directional movement, challenging assumptions about the “Indianization” of other cultures through Buddhism, and the “Sinification” of Buddhism within China.