A Geographic Analysis of Traders and Trade Goods in Japan’s Late Medieval Seto Inland Sea

Japan has traditionally been seen as an “isolated” country, often excluded from analyses of Asian trade and even ignored in its maritime influence on domestic trade. Examining both documentary and archaeological evidence in the late medieval periods (fourteenth to sixteenth centuries) reveals a thriving trade network of both domestic goods and items from the mainland. Analyzing this data through a Geographic Information System (GIS) provides important information about the transshipment hubs, the multidirectional flow of trade items between communities in the Inland Sea, and even the labor patterns of the captains that plied those waters. Those trade patterns were also influenced and used by domestic “pirates,” sometimes referred to as “sea lords,” who controlled certain areas in the Inland Sea. They were able to procure items for their own use, possibly outside of legitimate trade channels. The thriving domestic maritime trade revealed through this analysis paints a fuller picture of the networks within the Inland Sea before Japan’s contact with the West.