This article attempts to review the historical background of the oppidum, which emerged from about 150 BCE (the late European Iron Age to the late La Tene culture) and to examine some new perspectives and hypotheses on its role and function and furthermore, the reason of its sudden disappearance. Originally “oppidum (pl. oppida)” was a term used by Caesar in his De Bello Gallico, to describe a ‘town’ occupied by various Celtic tribes. Oppida tend to occupy at least more than 10 ha, in which various productive facilities, agricultural field, commercial facilities and sanctuaries are located in association with settlements. And thus, it has been assumed that the oppidum functioned as a central place for economic activities, as well as that of politics and religion. Focusing on this role and function, it has been acknowledged that the oppidum can be regarded as strong evidence of urbanization in Central Europe.
Contrary to the above, this article argues that it necessary to grasp the appearance of the hillfort sites of the Early phase of the Iron Age in Europe and of the oppidum of the Late phase within the context of the long-term process of growth in terms of individuals and communities that began with the Neolithic period in Europe. This article also stresses that, although the oppidum featured defensive walls, regarded as one of its roles, but it is still unclear whether such walls were of practical use in war. So to speak, it is proposed that the oppidum played the role of emphasizing communal identity by dividing the inside and the outside, and that it may have acted as a political, economic, and religious centre in the place where it was located in peaceful times. It is assumed, however, that its role as a defensive wall would have been restricted in wartime.
This inference is indirectly evidenced by the very limited remains of oppida that were destroyed by fire, as well as documents on real battle against the Roman army which were described by Caesar. Rather, the oppidum demonstrates to the power and authority of the ruling class, who led the construction and modification of the gates of oppida, which were enhanced and strengthened by such construction and modification processes.
The oppidum suddenly disappeared with the Roman conquest of the region. The reason for this is still unclear, but it can be presumed that, instead of being regarded as a centre which could control other neighboring towns, the oppidum was merely a bigger town among other peer towns. Therefore, one needs to grasp the oppidum within the context of a transitional phenomenon which involved the long-term process toward urbanization, rather than regarding it as an urban city itself in Central Europe.