Introduction

Processes of acculturation and assimilation in contact situations have been the subject of considerable interest to North American and Japanese prehistorians alike. In the latter case, research has emphasized the transition, beginning about 1000 BC, to the wet-rice-focussed Yayoi (Akazawa 1981, 1986) (see TABLE1 for plant nomenclature used in this paper). The spread of agriculture to northeastern Japan is usually viewed as a northeastward progression of a frmtier that reached northern Tohoku by the Middle Yayoi (FIGURES 1 & 2). However, the situation is more complex than this, in our view, and involves a spatial and cultural dichotomy between Hokkaido and northern Tohoku on the one hand and southern Tohokusouthwestern Japan on the other. Furthermore, we interpret Ainu culture (as distinct from the Ainu biological population) of Hokkaido and Sakhalin to be an outcome of a long period of social interaction along this boundary.

Introduction

During the Yayoi Period of Japan (approximately 300 BC to 300 AD) tropical shell bracelets appear in elite burials in Kyushu (FIGURE 1) .In this paper I discuss recent investigations which indicate that these shells were produced in Okinawa, some 500 km. to the southwest of Kyushu, and were exchanged for Yayoi pottery vessels and possibly other artefacts. The context of this exchange system and the implications for Japanese prehistory are also considered.

Mounded tomb burial for the elite is the hallmark of Japan’s Kofun period (AD 280-700) This is also known to be the period of state formation, and the burials of the paramount chiefs or early kings are concentrated in the present-day prefectures of Nara and Osaka. This centre of power will be referred to in this article as the ‘central court’, in contrast to the surrounding regions of western Honshu such as Kyoto, Hyogo, and Okayama prefectures, which also have many mounded tomb burials. The central court in the 4th century is often called the Miwa Court and in the 5th century the Kawachi Court. The extent of influence or control of the central court over the regions in these centuries is an issue addressed in the following discussion.

Thirty years after Glyn Daniel's perceptive publication on the ‘idea of prehistory’ (Daniel 1962), the topic is enjoying a return engagement in the archaeological literature. Not only have the sources of the words for ‘prehistory’ been traced in various languages (Chippindale 1988; Clermont & Smith 1990). but a new nuance has been added to the word ‘idea’. In the new chapters added to the re-issue of Daniel’s book, Renfrew uses the phrase ‘idea of prehistory’ to mean ‘a picture of the past’ or a ‘reconstruction of the past’ (Daniel & Renfrew 1988: 198, 203). In other words, Renfrew has subtly shifted the meaning of ‘idea’ from the concept of a time of human existence before the advent of written history, as I perceive Daniel originally used it, to an interpretation of what went on in that time period.