Book excerpt: This study focuses on the distribution of early Dong Son bronze drums, from their centres of production in north Vietnam throughout Mainland and Island Southeast Asia, as evidence of cultural contact and cross-regional exchange along river and maritime routes from the late Metal Age to the proto-historic period. This is the period just prior to, and overlapping with, the first Chinese and Indian influences in the wider region. The exchange of bronze drums established alliances between early centres favouring the trade of other goods. Such early centres allow us to identify early cultural spheres which set the stage for the process of state formation in the historic period. Adopting a synoptic view over the entire distribution across present national boundaries, the author analyses the implications of what types of drums are found where. As a working tool towards this goal, she identifies specific regional clusters. Each cluster of drums highlights and clarifies specific questions regarding chronology, routes of transmission, the geographical extent of trade networks, and new local bronze casting traditions arising from the influence of the imported bronze drums.