Abstract

Southeast Asia is a multiethnic region with a long history, as toponyms such as Suvarṇabhūmi were mentioned in Indian records as early as the third century BCE. This study utilized astronomy, geography, and linguistics to geolocate Southeast Asian states and geographical features during the period between the third century BCE and the fifth century CE, which covers its early historic period. Ptolemy’s Geography, which contains geographical knowledge from the early second century BCE, is the primary source of information from the Greek record. The results of astronomical computations from this ancient geographical corpus suggest that, in addition to the approximated locations derived from multiple navigators, the locations of some cities were likely computed using the date of the overhead Sun encoded with a type of local lunisolar calendar. Comparing the astronomically reconstructed maps to the modern map also indicates that Ptolemy’s coastline is roughly similar to the actual one and can be used to locate cities such as Takōla and Sabana emporia to a reasonable level of certainty. The results of the etymological analysis also indicate that some indigenous toponyms translated into Greek, Pali, and Sanskrit are still in use today.