4 Hillforts and Oppida from the Iron Age

Hillforts and Oppida are large structures dating to the Bronze and Iron Ages that performed a variety of defensive, cultural, and ritualistic functions.

Nov 3, 2023By Ben Hume, MA Funerary Archaeology, BA Archaeology
celtic hillforts oppida iron age
Artist’s interpretation of what Maiden Castle may have looked like during the Iron Age via BBC


Hillforts are large earthwork fortifications that are usually located on a high point in the landscape with commanding views across a wide area in order to provide a defensive advantage. They were are often formed from one or more defensive earthworks composed of ramparts and ditches. Hillforts were first used in Britain during the Bronze Age, although they rose in prominence during the Iron Age. They are comparable to the oppida, as the similar fort of continental Europe are called. The primary uses of hillforts is a topic of considerable debate within archaeology as their size and stature has often been considered only for their defensive capabilities whereas it is possible that they performed a variety of other functions as well such as for ritual and as statements of elite power. This article will examine the uses and significant historical events from two British hillforts and two French oppida.


1. The Hillfort of Danebury, Hampshire, England

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Danebury Hillfort in Hampshire has been subject to intensive archaeological excavations since the 1970s via Wikimedia Commons


Danebury hillfort is one of the most well studied hillforts in Britain and the earliest phase dates to the 6th century BCE. It evolved considerably over a period of a few hundred years and eventually took on the form as it appears today. This type of construction that consists of multiple rings of raised ramparts and deep ditches is called a multivallate hillfort.


The complex and maze-like network of earthworks would have presented a significant obstacle to anyone attempting to storm the fort. The weakest points in the fortification would have been the entrances, although this was compensated for through the creation of bottlenecks. The entrances were also strengthened by large fortified gateways that would have given defenders a wide view over the surrounding area in order to effectively defend the hillfort in the event of an attack. As well as defensive structures, large caches of slingshot balls (small round pebbles) were found deposited near to the eastern gate which could suggest that they were used as defensive weaponry in the event of an attack.


As well as the defensive hypothesis, the discovery of rectangular shrines at the center of the hillfort also suggests that it was used for ritual purposes. This is furthered by the discovery of human remains that had been deposited either as full inhumations or as disarticulated remains within grain storage pits across the hillfort.


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Recent research on some of the bones suggests that many were exposed to the elements and often removed from deposition which suggests that excarnation was a method used to dispose of the dead. This is interesting because the deposition of the remains is often in very close proximity to the domestic round houses, suggesting that there was a significant element of ritual practice at Danebury that was part of everyday life.


2. Maiden Castle, Dorset, England

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The Iron Age hillfort of Maiden Castle, via DK Findout


Maiden Castle in Dorset is one of England’s largest and most developed hillforts. Its banks of ramparts and ditches would possibly have been bright white during the Iron Age as the chalk of their construction was exposed. This would have provided an intimidating and impressive appearance for anyone coming near to the hillfort when the ramparts had been completed around the 1st century BCE.


Excavations in the 1930s revealed a large quantity of human remains which had strong evidence of trauma. This was initially interpreted by archaeologist Mortimer Wheeler as evidence of the Roman invasion of Britain and claimed it had been conquered by the future emperor Vespasian. Mortimer then created a narrative of the outnumbered Britons being ruthlessly destroyed by the Roman legions. His purely militaristic view of Maiden Castle was likely influenced by his own military experience.


A more recent study, however, has re-examined the assemblage and has taken into account the possibility of inter-tribal warfare. Strong evidence of the healing of injuries has shed light on the fact that the Iron Age was generally a violent period, and conflict would have been commonplace. The Durotriges tribe who inhabited Maiden Castle often faced conflict with neighboring tribes, and the evidence of combat was significantly higher than in surrounding cemeteries in the same region. It is not possible to prove that there was a full-scale assault of Maiden Castle by Vespasian’s legions, although one individual was discovered with a Roman ballista point embedded in his spine which does provide evidence of conflict. This however, could have taken place away from the hillfort during a skirmish in a different area.


3. The Oppidum of Alesia, Alise-Sainte-Reine, France

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Vercingetorix Throws Down His Arms at the Feet of Caesar, by Lionel Royer, 1899, via Le Puy-en-Velay, Musée Crozatier


In comparison to English hillforts, oppida in continental Europe were generally built on a larger scale and took on this Latinised name in contemporary and later Roman writings. They are defined better as a fortified settlement and were often encircled by a murus gallicus which is a strong defensive wall constructed from jointed wooden crossbeams, an earth or rubble fill and an outer stone facing. When placed on the top of a hill, they provided a strong and defensible position that was difficult to besiege. The oppidum at Alesia was the stage for one of the most famous battles in Roman history and led to the conclusion of Julius Caesar’s Gallic wars in 52 BCE with the defeat of the Arverni king, Vercingetorix, who had united the Gallic tribes in a revolt against Rome.


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Reconstruction of Caesar’s fortification at Alesia, via Wikimedia Commons


Having pursued Vercingetorix for some time after many battles and skirmishes, Caesar eventually trapped him within the walls of Alesia for a period of two months. He then ordered the construction of walls and ramparts around the circumference of the oppida in order to ensure that the defenders and any reinforcements would be unable to coordinate an attack. The Gallic reinforcements led by Vercassivellaunus (possibly the cousin of Vercingetorix) launched an attack against a proposed weak spot in the Roman defenses but were eventually defeated after Caesar rallied the defenders for a decisive and bloody battle. The defeat of the reinforcements led to the surrender of the defenders trapped in Alesia and to the eventual death of Vercingetorix, who was paraded through the streets of Rome and then executed during Caesar’s victory parade in 46 BCE.


4. The Oppidum of Bibracte, Saône-et-Loire, France

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The reconstructed murus gallicus from the oppidum of Bibracte via Wikimedia Commons


The oppidum of Bibracte was also of great significance during Caesar’s Gallic wars, where he defeated the Helvetii, who had begun to migrate across the lands of the Aedui, leading to the Battle of Bibracte in 58 BCE. A wide range of military artifacts have been recovered from the site such as fragments of gladius swords, parts of catapults and slingshot balls. The oppidum was also of cultural importance and grew into a large center of commerce that thrived due to its trade links with the Mediterranean. It also became an important location for metallurgy, with large forges and blacksmithing workshops scattered throughout the site. Craft specialisms and large trade networks allowed Bibracte to grow into a strong cultural capital and to generate wealth and power that had a distinct impact on its political prowess.


Bibracte was only occupied for a relatively short period of time that ranged from the 2nd to the 1st century BCE. Despite this, the oppidum rose to great importance during its century of existence and was encircled by a double rampart and had districts that extended over 200 hectares, accommodating somewhere between five and ten thousand people. As the Aedui were allied to Rome, it was seen as important for them to have a Roman capital. The town of Augustodunum was therefore built by the emperor Augustus which led to the eventual abandonment of the oppidum of Bibracte.


What was the Function of Hillforts and Oppida?

dudsbury hillfort artist interpretation

An artist’s interpretation of what daily life within Dudsbury Hillfort in Dorset may have looked like. Tall ramparts and wooden walls would have been a common feature across many hillforts, via Kenning Illustration

When analyzing the various uses of hillforts, it is important to remember that only a tiny fraction of known hillforts have been excavated, and in some cases, no archaeological work has been completed at all. This makes it difficult and hazardous to create narratives surrounding their use when applied to other examples in different areas. Despite this, however, it would appear that the hillforts and oppida considered in this article all performed a wide range of functions that cannot be tied down into a single idea.


The large scale of their construction with ramparts, ditches and murus gallicus certainly presented any attacking force with a difficult obstacle to overcome when attempting any form of attack. It is, however, important to also consider the wider variety of functions that hillforts and oppida were used for in terms of being powerful status symbols, political centers, and trade hubs for craft production. Furthermore, for much of their use, they were places where common people lived in their houses in a capital that was definitively tied to tribal identities. Due to this fact, there is a wealth of archaeological evidence for ritual practices such as shrines and domestic features in the form of houses and workshops.

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By Ben HumeMA Funerary Archaeology, BA ArchaeologyBen is an archaeologist specializing in funerary practices and the Iron Age with MA and BA degrees from the University of York. He received an award for his MA dissertation considering evidence of violence on human remains in northern Britain's Bronze and Iron Age caves, which is now being reworked for publication. Ben has also worked in post-excavation and the museum sector to record and exhibit archaeological material. Ben can usually be found hiking up the nearest mountain or traveling when not working.