The Izu Islands: Their Role in the Historical Development of Ancient Japan

Abstract

Four areas in which the Izu Islands played an important role in Japanese historical development are discussed in detail. The first of these is the obsidian trade from the source on Kozu Island that was exploited from the Palaeolithic until the Yayoi period. Kozu obsidian was distributed widely through central Honshu and was of major economic significance to the prehistoric inhabitants of this region. Another item traded from the Izu Islands was the limpet Penepatella, which was used to make bracelets that were spread through eastern Japan from the Initial Jomon until the end of the Kofun period. After the formation of the Yamato state, the Izu Islands took on a new importance because of their strategic geographic position on the sea route to the east. The presence of a number of ritual sites in the Izu Islands and on the Izu Peninsula can be explained by this political need to maintain communication routes from the capital to the eastern provinces. Finally. in the Ritsuryo period the Islands became known as one of the major sources of ritual groups specializing in turtle shell divination. Historical records show that individual diviners from the Islands played an important part in court rituals held in the capital. KEYWORDS: Japanese archaeology, Izu Islands. obsidian and shell exchange, ritual interaction.