Historic Routes to Angkor: Development of the Khmer Road System (Ninth to Thirteenth Centuries AD) in Mainland Southeast Asia
Hendrickson, Mitch, Antiquity
Ancient road systems: context and methods of study
Investigating the chronology of road systems is complicated by their frequent reuse over long time periods and because they are comprised of multiple archaeological components that range from site to regional scales (e.g. roads, resting places, crossing points, settlements, ceramics). The archaeologist studying road systems must identify and incorporate a variety of available data sets, including historic information, within a framework of operational principles that characterise state-level road building and use. Recent trends in the study of imperial states focus on socio-cultural issues, such as power and politico-economic organisation (see D'Altroy 1992; Sinopoli 1994; Morrison 2001) and concepts of boundaries (see Morrison 2001; Smith 2005). An important characteristic underpinning these studies is that all states experience stages of expansion, consolidation and collapse occurring at different time scales (see Marcus 1992; Sinopoli 1994: 162-9).
In relation to state-level transportation, the concept of development has been discussed in the context of road systems built during the Roman period in Britain and mainland Europe (Forbes 1964; Margary 1967; Chevallier 1976), in early Imperial China (Needham et al. 1971), in Inka South America (Hyslop 1984) and protohistoric to Mughal India (Deloche 1993). From these studies four operational principles emerge. Firstly, later groups tend to reuse routes rather than construct new ones. Routes used by the Inka often show evidence that they were initiated by pre-state (Chavin 900-200 BC) or early state (Wari AD 700-1100) societies (Hyslop 1984: 271-2). Reuse may continue to the present day: many roads in Western Europe follow lines established during Roman and even pre-Roman times (Dowdle 1987: 270, 277). In Cambodia, National Route 6 is built today over an Angkorian period road.
Secondly, all routes within a system are not continuously or universally used throughout their history. States are prone to shift emphasis from individual roads and, in more extreme cases, switch to different modes of transport such as the post-Han emphasis on riverine networks over the terrestrial system (Needham et al. 1971: 30). Thirdly, the type and distribution of infrastructure and transport technology (i.e. road type, crossing type) are rarely homogeneous across an entire system, often varying according to terrain and distance from core territories. Different forms of road construction are employed across the Inka system (Hyslop 1984: 225-8) and the European and Middle Eastern roads of the Roman Empire (Chevallier 1976: 93; Graf 1997: 125).
The fourth principle is that road systems require substantial effort and resources for their construction and maintenance. Motivation for, and ability to create and/or formalise, a road system is therefore linked to periods of economic/political expansion and consolidation and access to sufficient manpower. Roman road-building and improvement corresponded to military advances and reigns of emperors such as Augustus or Hadrian; by contrast little roadwork was undertaken during times of civil unrest (Forbes 1964: 124-9; Margary 1967: 504). Imperial roads in China were founded in the first consolidation by the Qin (221-206 BC) and later expanded to their greatest extent during the long period of Han control (206 BC-AD 220) (Needham et al. 1971: 5-27).
In combination these principles provide the foundation for identifying development within transportation systems of the past. Here we apply these principles to the road system of the Khmer Empire where we will not only identify internal development but demonstrate the importance of including roads within comparative discussions of these complex societies.
The Khmer road system
The core of the Khmer Empire (ninth to fifteenth centuries AD) was controlled from the capital of Angkor through the extensive river network and over 1000km of raised earthen roads fitted with support infrastructure (masonry bridges, 'resthouse' temples, water tanks) (Figure 1). …