The Celts and Urbanization

The Enduring Puzzle of the Oppida

By: Elizabeth Hamilton

Originally Published in 2003

View PDF

Archaeologists have speculated for decades about the role of Celtic settlements called oppida, because they fit only loosely into the category we call “urban.” Unlike the people of the Middle East, who possessed large cities such as Ur, Babylon, and Tyre, among many others, the people of Europe north of the Alps preferred to cluster in small villages or hillforts, with their ritual sites out in the countryside. During most of the Bronze and Iron Ages, both southwest Asia and Europe north of the Alps were densely populated, socially stratified, and crossed by established trade networks, but only in the last two centuries B.C. do we see what may have been the first towns north of the Alps, the oppida. Although these were the largest and most complex sites in temperate Europe before the coming of the Romans, their scale remained modest, and the question of why they did not become cities continues to be a puzzle.

Growth and Change in Iron Age Settlements

The Early Iron Age, the Hallstatt C-D Period (700 B.C.–450 B.C.), was characterized by wealthy “princely” graves and for­tified hillforts, the most elaborate of which is described by Bettina Arnold on page 8. From about 450 B.C. to 200 B.C., though, most people settled in undefended lowland villages. This period saw the introduction and spread of the La Tène art style, after which the Middle and Late Iron Age period is named. This swirling, almost hallucinogenic style of orna­ment is widely associated with Celtic-speaking people (see Bernard Wailes’ article on page 26), and by the end of the third century B.C. it is found from Central Anatolia to Ireland and from southern France to southern Poland. Although Celtic speakers certainly did not occupy all of this wide area, the rapidity of the spread and the similarity of the ornaments and vessels found so many miles apart are a testament to the wide­spread trading networks of the Celtic world.

In the second century B.C. we see the abrupt reappearance of the fortified hilltop site, but on a much vaster scale. The wall of the Hallstatt Period Heuneberg in Germany enclosed an area of 7.5 hectares (18 acres); in contrast, the wall of the Heidengraben in southern Germany covers 1,500 hectares (3,705 acres). The sites are located on prominent hills, in river bends, or at the edges of swamps. In most cases, they were new establishments, and often the low-lying unfortified villages near them were abandoned. Presumably the popula­tion moved into the new oppida. At the same time we see signs of greatly increased trade with the Mediterranean world, especially in wine and drinking equipment.

The fortifications of these new settlements were massive. Even today, 2,000 years after the abandonment of the defenses, the earthen rampart of the Titelberg in Luxembourg stands 10 meters high and 40 to 50 meters wide at the base. The exact type of defense varied geographically, but the type described by Caesar, the murus gallicus, or Gallic wall, con­sisted of an earthen rampart with internal timber lacing fastened together with thousands of long iron spikes. The timber-laced ram­part was then faced with stone blocks. It has been estimated that it took 200,000–435,000 working hours to construct the 5-kilometer-long murus gallicus around the oppidum of Bibracte (Mont Beuvray, France).

In most cases these huge walls enclosed an area far larger than was actually inhabited. It has always been assumed from Caesar’s accounts that these oppida served as refuges for the rural population in times of war, and thus in normal times would have had a great deal of excess land. But what is puzzling is that in some cases the walls enclose an area so large as to be indefensible. Clearly more is involved than straightforward defense. Perhaps the walls of the oppida reflect a trend seen in many Late Iron Age structures from palisaded farmsteads to ditched and palisaded ritual sites: a concern with boundaries, a desire to definitively mark terrain and separate categories of territory. Likewise, the wall builders could have also have been concerned with display, a sort of “our wall is bigger” competition.

The Oppida and Politics

The classical writers, especially Caesar, described Celtic soci­ety as highly stratified and oppressive. The only two groups who counted were the nobles and the druids, who acted as religious leaders and judges. The common people were at the bottom, regarded almost as slaves, with no voice in affairs, and serving the nobles in a patron-client relationship. We also know that some Gauls, the Celtic peoples of what is now France, were traders and specialist craftspeople who may have owed some allegiance to a noble but who probably conducted much of their craft work independently.

It is likely that some of the Celtic tribal polities had reached the status of states at the time of Caesar’s invasion, especially the tribes of central France. What differentiates the Celtic states from those in the Mediterranean is that the Celtic states were tribal, not based on a city-state. A city-state is a fixed territory; a tribal state is based on a potentially movable population and can include many political and eco­nomic centers. Caesar noted that each tribe possessed numerous oppida, and while some oppida were described as especially beautiful or important, none was described as a political center. Indeed, though few oppida have undergone broad horizontal excavations, it is rare to find large public buildings or even areas of public assembly in those that have been excavated. Caesar noted that particular oppida were the dependencies of certain nobles, which is in keeping with the oligarchic nature of the polity. When the coins produced in the oppida and other sites are inscribed, the name they bear is not a tribal name, or even a town name, but the name of the issuing magistrate or chieftain.

Life in the Oppida

What would we see if we were to walk into an oppidum? There is no typical oppidum, but we will take as examples several of the largest and most prominent.

The site would be completely surrounded by walls of earth and stone, topped by a wooden palisade. The walls would have one or more massive pincer gates topped by a watch­tower and designed to control the flow of people in and out. The oppidum is bisected by an unpaved main street that leads from the main gate to a gate on the other side; other straight streets, evidence of a planned layout, cross the main road. In some oppida such as Bibracte (Mont Beuvray), and Zavist and Stradonice (Bohemia), what seem to be workshops and craft areas are found clustered on the main road near the gate. Here the bronze and iron smiths, the workers in bone and leather, and the makers of fine pottery and glass would have their shops and sell their wares.

Passing the workshop area, you would emerge not into a dense network of public buildings and assembly areas but into streets lined with small houses and palisaded enclosures containing one or two houses, along with granaries, storage pits, and probably stock pens for chickens, pigs, and other domestic animals. In their layout, the enclosures and the buildings within were very like the isolated farmsteads found in the countryside. Often traces of craft production are found within these enclo­sures. Most of the rest of the land enclosed by the defensive ramparts would be used for farming and pasture.

In a few sites there is evidence for what may be public build­ings. In Villeneuve-Saint-Germain (France), the oppidum is crossed by two intersecting trenches, 500 and 300 meters long, 1.4 meters deep, and 2 meters wide, dividing the site into four unequal areas. Rows of postholes follow the trenches, showing that they were covered by a wooden structure. Many traces of fibulae (brooches) in various stages of manufacture are found near the covered trenches. Other areas nearby have traces of fur and leather working. Were these enigmatic covered trench­es the site of workshops or markets?

In Manching (Germany), the area known as Complex B was a giant enclosed area some 80 meters on one side and sur­rounded on three sides by streets. The enclosure contained seven long houses; the longest two were 44 meters long and 6 meters wide. The roofed wall around the complex was pierced at one point by a gate and a guardroom. The purpose of this complex is unknown. Was it an aristocratic residence? Were the buildings warehouses for trade goods?

Inside the oppidum would be cult areas as well. The forms vary, but most contain elements of enclosures, ritual deposits in ditches, and sometimes human sacrifice. Frequently what appear to be ritual deposits of human and animal bones and broken weapons are found in the ditches. Gournay-sur-Aronde in France has an enclosure with sides 40 meters long and with a palisade that concealed the interior from the populace. Found in the ditch were hundreds of deliberately broken weapons, many bones of large animals, and the bones of 12 decapitated humans. In an enclosure at Ribemont-sur-Ancre (France), an entire structure was built of the long bones of some 200 people, mostly young men. In the Titelberg (Luxembourg) a ritual area covering at least a third of the site was demarcated by a trench; inside is an enclosure marked by ditches containing numerous fibulae and coins.

The rural character of these settlements is striking. The buildings are of wood and thatched with straw. Structures, with exceptions such as Complex B at Manching, were not densely packed together. Most households probably produced their own food and crafts, and even the specialist craftspeople probably grew crops and grazed animals. Few settlements had imposing monumental structures as a central focus.

What is an Oppidum?

Two sources tell us about oppida: the archaeological record and written records, especially those of Julius Caesar. Indeed, the word oppidum comes from Caesar’s The Battle for Gaul, where he refers to fortified Gallic strongholds. Oppidum simply means “town” in Latin, and its usage implies that Caesar recognized similarities between the oppida and the town centers familiar to him from the Roman world.

Unfortunately for us, Caesar was not writing a cultural account but a war report largely composed for propaganda and to justify his invasions. Also, Caesar was observing the Gallic landscape during a time of trauma (that he caused), so what he reports may not have been representative of the oppida 10 years earlier. In addition, his use of the term oppida is inconsistent; when describing his British cam­paigns, he uses it to refer to smaller fortified sites with no permanent population.

To better solve the oppidum puzzle, we must rely upon archaeology. English-speaking archaeologists define an oppidum as a site from 20 to over 1,000 hectares large (1 hectare=2.47 acres) that is entirely surrounded by fortifications, both natural (rivers, cliffs, and swamps) and constructed. (French archaeologists use oppidum to refer to any hillfort of this period.) Often located on high ground, the oppida have a commanding view of the surrounding terrain. We find sites of this kind from the Czech Republic to southern France to southern Britain. Some of these sites, such as Bibracte in France, Manching in Germany, and Stradonice in Bohemia, had dense permanent populations of several thousand and were clearly centers of industrial production. Others, such as Kelheim in Bavaria and Závist in Bohemia, seem to have been only thinly populated.

Most oppida were located near trade routes or natural resources, especially iron ore. There is evidence that certain oppida specialized in the production of various goods, such as salt, fine pottery, and glass. Many oppida produced both raw iron and finished iron and steel articles that were highly regarded in Rome for their quality. Many of the oppida pro­duced coins. But to add to the confusion, some unfortified sites were clearly large industrial centers as well, and many produced coins. Nor is it clear from excavations how much even the well-populated oppida would have conformed to our definition of urban, which usually assumes that the site was, first, a center of public or administrative life, second, occupied permanently by at least 1,000 people, and third, divided into zones with different functions.

Cite This Article

Hamilton, Elizabeth. "The Celts and Urbanization." Expedition Magazine 45, no. 1 (March, 2003): -. Accessed February 22, 2024.

This digitized article is presented here as a historical reference and may not reflect the current views of the Penn Museum.

Report problems and issues to