An oppidum (plural oppida) is a large defended Iron Age settlement. They emerged in the 2nd and 1st centuries BC and spread across Europe, stretching from Britain and Iberia in the west to the edge of the Hungarian plain in the east. They continued in use until the Romans began conquering Europe. North of the River Danube, where the population remained independent from Rome, oppida continued to be used into the 1st century.
Oppidum is a Latin word meaning the main settlement in any administrative area of ancient Rome. The word is derived from the earlier Latin ob-pedum, "enclosed space," possibly from the Proto-Indo-European *pedóm-, "occupied space" or "footprint." Julius Caesar described the larger Celtic Iron Age settlements he encountered in Gaul as oppida, and the term is now used to describe the large pre-Roman towns that existed all across western and central Europe.
In archaeology and pre-history, the term oppida refers to a category of settlement; it was first used in this sense by Reinecke, Dechelette and Dehn in reference to Bibracte, Manching, and Závist. Most definitions of oppida emphasise the presence of fortifications, so they are different from undefended farms or settlements; and urban characteristics, marking them as separate from hill forts. They originated in the 2nd and 1st centuries BC, a product of Europe's La Tène culture and a notional minimum size of 20 to 25 hectares (49 to 62 acres) has often been suggested, although it is flexible and fortified sites as small as 2 hectares (4.9 acres) have been described as oppida. However, the term is not always rigorously used, and has been used to refer to any hill fort dating from the La Tène period. One of the effects of this inconsistency in definitions is that it is uncertain how many oppida were built.
Location and type 
According to prehistorian John Collis oppida extend as far east as the Hungarian plain where other settlement types take over. Central Spain has sites similar to oppida, but while they share features such as size and defensive ramparts the interior was arranged differently.
The main features of the oppida are the walls and gates, the spacious layout, and commanding view of the surrounding area. According to Jane McIntosh, the "impressive ramparts with elaborate gateways ... were probably as much for show and for controlling the movement of people and goods as for defense [sic]".
Size and construction varied considerably. Typically oppida in Bohemia and Bavaria were much larger than those found in the north and west of France. Typically oppida in Britain are small, but there is a group of large oppida in the south east; though oppida are uncommon in northern Britain, Stanwick stands out as an unusual example as it covers 350 hectares (860 acres). Stone walls supported by a bank of earth, called Kelheim ramparts, were characteristic of oppida in central Europe. To the east timbers were often used to support the earthen ramparts, called the Preist type. In western Europe, the murus gallicus, a timber frame nailed together, was the dominant form of rampart construction. Dump ramparts, that is earth unsupported by timber, were common in Britain and were later adopted in France. Oppida can be divided into two broad groups, those around the Mediterranean coast and those further inland. The latter group were larger, more varied, and spaced further apart.
Prehistoric Europe saw a growing population. According to Jane McIntosh, in about 5,000 BC during the Neolithic between 2 million and 5 million lived in Europe; in the Late [Pre-Roman] Iron Age (2nd and 1st centuries B.C.) it had an estimated population of around 15 to 30 million. Outside Greece and Italy, which were more densely populated, the vast majority of settlements in the Iron Age were small, with perhaps no more than 50 inhabitants. While hill forts could accommodate up to 1,000 people, oppida in the Late Iron Age could reach as large as 10,000 inhabitants.
Oppida originated in the 2nd and 1st centuries BC. Most were built on fresh sites, usually on an elevated position. Such a location would have allowed the settlement to dominate nearby trade routes and may also have been important as a symbol of control of the area. For instance at the oppidum of Ulaca in Spain the height of the ramparts is not uniform: those overlooking the valley are considerably higher than those facing towards the mountains in the area. The traditional explanation is that the smaller ramparts were unfinished because the region was invaded by the Romans; however, archaeologist John Collis dismisses this explanation because the inhabitants managed to build a second rampart extending the site by 20 hectares (49 acres) to cover an area of 80 hectares (200 acres). Instead he believes the role of the ramparts as a status symbol may have been more important than their defensive qualities.
While some oppida grew from hill forts, by no means all of them had significant defensive functions. The development of oppida was a milestone in the urbanisation of the continent as they were the first large settlements north of the Mediterranean that could genuinely be described as towns. Caesar pointed out that each tribe of Gaul would have several oppida but that they were not all of equal importance, perhaps implying some form of settlement hierarchy.
Oppida continued in use until the Romans began conquering Iron Age Europe. In Germany north of the River Danube, which remained unsubdued by the Romans, oppida continued in use until the late 1st century AD. In conquered lands, the Romans used the infrastructure of the oppida to administer the empire, and many became full Roman towns. This often involved a change of location from the hilltop into the plain.
The Low Countries 
Central and eastern Europe 
British Isles 
- Woolf (1993), pp. 223–224
- Jones (2001), p. 46
- Woolf (1993), pp. 224–225
- Woolf (1993), p. 225
- Collis (2000), pp. 229–230
- McIntosh (2009), p. 156
- Woolf (1993), pp. 225–226
- Collis (2000), p. 238
- McIntosh (2009), p. 349
- McIntosh (2009), p. 349
- McIntosh (2009), p. 349
- Collis (2010), p. 31
- Collis, John (2000), "'Celtic' Oppida", in Hansen, Mogens Herman, A Comparative Study of Thirty City-state Cultures, Det Kongelige Danske Videnskabernes Selskab, pp. 229–240, ISBN 87-7876-177-8
- Collis, John (2010), "Why do we still dig Iron Age ramparts?" (PDF), Collection Bibracte 19: 27–36, ISBN 978-2-909668-64-2
- Jones, Stephen (2001) Deconstructing the Celts: a skeptic's guide to the archaeology of the Auvergne. British Archaeological Reports. Oxford: Archaeopress. ISBN 978-1-84171-252-9
- McIntosh, Jane (2009) Handbook of Life in Prehistoric Europe (paperback ed.). Oxford: Oxford University Press. ISBN 978-0-19-538476-5
- Woolf, Greg (July 1993), "Rethinking the Oppida", Oxford Journal of Archaeology 12: 223–234
Further reading 
- Collis, John (1984), Oppida, earliest towns north of the Alps, Department of Prehistory and Archaeology, University of Sheffield, ISBN 9780906090237
- Cunliffe, Barry & Rowley, Trevor (eds.) (1976) Oppida, the Beginnings of Urbanisation in Barbarian Europe: Papers Presented to a Conference at Oxford, October 1975. British Archaeological Reports. Oxford: Archaeopress.
- Garcia, Dominique (2004) La Celtique Méditeranée: habitats et sociétés en Languedoc et en Provence, VIIIe–IIe siècles av. J.–C. chapter 4 La « civilisation des oppida » : dynamique et chronologie. Paris, Editions Errance. ISBN 2-87772-286-4
- Sabatino Moscati, Otto Hermann Frey, Venceslas Kruta, Barry Raftery, Miklos Szabo (eds.) (1998) The Celts, Rizzoli