Low-Density Urbanisation: Prestate Settlement Growth in a Pacific Society

The recognition of low-density urbanisation has been important in documenting how diverse human settlements generated enduring social and economic change. In tropical regions, the key challenges to studying low-density urbanisation have been the difficulty in acquiring past built environment data and integrating the frameworks that illuminate the social behaviours intrinsic to urbanisation. The introduction of lidar mapping and urban science methods has proven revolutionary in our understanding of low-density urbanisation as demonstrated by emerging research on settlements and states in Mesoamerica and Southeast Asia. These studies draw on urban theory to highlight patterns in the built environment associated with profound societal changes including the rise of social institutions, agglomeration effects, and ongoing settlement growth. Here, we present an approach that combines lidar survey and archaeological fieldwork with recent developments in urban science to understand the built environment of Tongatapu; the location of an archaic state whose influence spread across the southwest Pacific Ocean between the thirteenth and nineteenth centuries a.d. Quantitative results show—for the first time—that settlements on a Pacific island were urbanised in a distinct low-density form and that the processes of urbanisation began prior to state development. This study highlights the potential contribution of Pacific landscapes to urban science and the low-density settlement phenomena given the presence of large populations, hierarchical societies, and vast distributions of archaeological built remains on many island groups.