Blog Post

Britain’s Giant Prehistoric Waterways

Introduction

Unmasking the Shared Secrets of Offa’s Dyke, Wansdyke, Car Dyke, and the Vallum

For centuries, the great linear earthworks of Britain – Offa’s Dyke, Wansdyke, Car Dyke, and Hadrian’s Wall’s Vallum – have been shrouded in mystery, often interpreted as defensive barriers or territorial markers. However, groundbreaking research utilizing LiDAR technology and re-evaluating archaeological evidence reveals a fascinating shared secret. These monumental structures bear compelling evidence of a significant relationship with water at various stages of their development, challenging conventional understandings of prehistoric and Roman Britain. (Britain’s Giant Prehistoric Waterways)

Let’s delve into the individual investigations of these four colossal “dykes” to uncover their watery past and shared characteristics:

(Britain's Giant Prehistoric Waterways)
Car Dyke – (Britain’s Giant Prehistoric Waterways)

Car Dyke: The Undeniable Waterway

Car Dyke, stretching across the Fens of Eastern England, has long puzzled historians. Unlike the other three, Car Dyke’s historical narrative has often acknowledged its role as a waterway, albeit primarily attributed to Roman engineering. However, recent investigations, including LiDAR surveys, reveal a more complex and ancient story.

  • Direct Evidence of Water Retention and Navigation: AI analysis even admits that Car Dyke shows empirical evidence of intentional water retention, with ditches designed for drainage and navigation. Our research confirms this, highlighting its function as a transportation hub for boats carrying men and materials.
  • Connection to Rivers and Springs: Car Dyke’s course appears to hug the shoreline, seemingly looking for natural springs to fill the canal. It has direct links to existing or prehistoric rivers created from post-glacial flooding. LiDAR mapping has further revealed its connections to other Roman sites and infrastructure, emphasizing its strategic importance within a network of waterways.
  • Prehistoric Origins and Water Use: Mathematical analysis of artefacts suggests that Car Dyke predates the Roman period, potentially having Mesolithic/Neolithic origins. This aligns with the broader theory that prehistoric societies utilized waterways extensively for transport. The “wobbly” nature of much of the Dyke’s course further hints at an adaptation of earlier natural water features.

(Britain’s Giant Prehistoric Waterways)

(Britain's Giant Prehistoric Waterways)
Offa’s Dyke in the Neolithic (Britain’s Giant Prehistoric Waterways)

Offa’s Dyke: More Canal Than Combat Barrier

Offa’s Dyke, famously dividing England and Wales, has traditionally been seen as a massive defensive earthwork. However, detailed LiDAR studies are dismantling this long-held belief.

  • Discontinuity and “Wrong-Facing” Defences: Our LiDAR surveys reveal that a significant portion of what is thought to be Offa’s Dyke is either missing (66% with over 70 gaps) or linked to natural river formations. Additionally, sections of the ditch face the “wrong way” if its primary purpose was defence.
  • Connection to Quarries and Rivers: A consistent pattern emerges: Offa’s Dyke shows a strong association with numerous quarries (48 identified within 200m in one section) and connections to both existing rivers and prehistoric paleochannels. This strongly suggests its use as a canal system to transport mined minerals.
  • Springs and Water Replenishment: Investigations have identified numerous springs along the alignment of Offa’s Dyke (17 in one section), indicating an intentional placement near water sources. This supports the idea that the “dyke” could trap and replenish water, functioning as a canal. The presence of potential “ponds” and connecting channels further hints at a prehistoric lock system to navigate elevation changes.
  • Adaptation of Prehistoric Waterways: Like Car Dyke, mathematical analysis suggests that parts of Offa’s Dyke are likely of Mesolithic/Neolithic origin, reused and potentially modified by later periods, including the Romans.
(Britain's Giant Prehistoric Waterways)
Wansdyke design shows its not for defence or a land marker – (Britain’s Giant Prehistoric Waterways)

Wansdyke: An Island’s Watery Embrace

Wansdyke, with its two main sections across Wiltshire, has also been conventionally interpreted as a Saxon defensive structure—however, our LiDAR surveys and analysis point towards a more intricate relationship with water.

  • Proximity to Prehistoric Waterways: Wansdyke’s location is significant: East Wansdyke runs between Savernake Forest and Morgan’s Hill, while West Wansdyke extends towards Bristol. Importantly, Wansdyke was potentially an island during the Mesolithic period, surrounded by the waters of the River Kennet.
  • Connection to Springs and Pits: LiDAR surveys reveal a notable number of springs and pits/quarries close to Wansdyke, similar to Offa’s Dyke. The consistent mathematics assigning a mining site to every 7 meters of Dyke suggests an intentional link.
  • Potential for Boat Travel: The western end of Wansdyke, situated within a prehistoric island, intriguingly splits the landmass, raising the possibility of boats sailing from end to end during the Mesolithic era.
  • Roman Adaptation: Evidence suggests that the Romans likely reworked sections of Wansdyke, creating a more cohesive structure. However, its underlying origins appear to be linked to prehistoric water management and transport during higher river levels.

(Britain's Giant Prehistoric Waterways)
Parts of the Vallum still contain water today – (Britain’s Giant Prehistoric Waterways)

The Vallum: Hadrian’s Watery Companion

The Vallum, a significant earthwork associated with Hadrian’s Wall, is often seen as a linear barrier south of the wall. While its Roman origin is widely accepted, its function is debated. Our research suggests that, like the other dykes, the Vallum also has strong connections to water.

  • Water Retention in the Ditch: AI analysis indicates that sections of the Vallum ditch show empirical evidence of water retention.
  • Connection to Springs and Water Sources: LiDAR investigations reveal a significantly higher number of springs (460% more than the norm) and quarries (180% more than the norm) near the Vallum. This mirrors the pattern observed with Offa’s and Wansdyke. The Vallum also connects with the Eden River and Brunstock Beck.
  • Paleochannel Connections and Potential for Canal Use: Paleochannels seem to connect Roman temporary forts near the Vallum, suggesting a potential for waterborne movement. The presence of a bridge and castle named after “Drawsdyke” further points to a historical association with a water-filled ditch. It’s plausible that the Romans, known for their engineering prowess, utilized a pre-existing prehistoric dyke for water management and the transport of materials for Hadrian’s Wall, similar to their adaptation of other British Dykes.

(Britain's Giant Prehistoric Waterways)

Shared Features and a New Perspective

Examining these four major linear earthworks collectively reveals compelling shared features indicative of a significant relationship with water:

  • Proximity to Water Sources: All four “dykes” exhibit a notable association with springs, existing rivers, and prehistoric paleochannels.
  • Links to Quarries: A strong connection exists between these earthworks and numerous quarries, suggesting a function in transporting quarried materials.
  • Evidence Against Solely Defensive Purposes: Discontinuities, “wrong-facing” ditches, and locations that would be illogical for defence suggest alternative primary functions.
  • Potential for Water Retention and Navigation: Evidence of ditch design and historical accounts (especially for Car Dyke) indicate the capacity for water retention and boat transport.
  • Likely Prehistoric Origins: Mathematical analysis and the “wobbly” nature of some sections suggest that these “Roman” or “Saxon” structures often have much earlier, possibly Mesolithic/Neolithic, origins linked to a landscape with significantly higher river levels due to post-glacial flooding.Introduction

Arles Rhône 3,

In 2004, archaeologists working near Arles in southern France discovered a remarkable Roman barge buried in the silt of the Rhône River. Named the Arles Rhône 3, this 1st-century AD vessel is a masterpiece of Roman-era inland water transport. But beyond its craftsmanship lies a deeper story—one that could reshape how we view Britain’s ancient linear earthworks.

Was this boat design truly Roman? Or did it originate earlier, as part of a pan-European river and canal culture? And if so, could Britain’s dykes and waterways—like the Car Dyke, Wansdyke, and the Vallum—have used similar vessels? Let’s dive in. (Rhône to Wansdyke).

From the Rhône to Wansdyke
Arles Rhône 3– From the Rhône to Wansdyke

The Arles Rhône 3: A Flat-Bottomed Marvel

The Arles Rhône 3 is about 31 meters long and 3 meters wide, with a flat-bottomed hull, shallow draft, and a side rudder for steering. These traits make it ideal for shallow rivers and canals—not the open sea. It was built with robust oak planks using mortise-and-tenon joinery, a technique consistent with Roman construction standards, though not unique to them.

This barge wasn’t designed for speed or waves. It was built to carry cargo—up to 30 tonnes—downriver efficiently, and then be towed back upstream by oxen, slaves, or ropes along towpaths. This was standard practice across the empire.

But here’s the crucial detail: this design predates Roman occupation. Flat-bottomed boats were used by Gauls and other European cultures for centuries before the Romans arrived. The Romans didn’t invent the design—they simply adopted and refined it. (Rhône to Wansdyke).

From the Rhône to Wansdyke
Arles Rhône 3– From the Rhône to Wansdyke

Roman Shipbuilding: The Great Inheritor

The Romans were not seafaring pioneers. Their naval tradition was built by copying and improving on the technologies of others—Carthaginians, Greeks, Celts, and Phoenicians. Even the famed Roman quinqueremes were based on captured Carthaginian ships.

What the Romans excelled at was standardisation and replication. Once they saw something that worked—be it a road, aqueduct, or barge—they duplicated it across the empire. The Arles Rhône 3 represents not an isolated invention, but a functional watercraft refined for mass deployment across inland Europe. (Rhône to Wansdyke).

From the Rhône to Wansdyke
Arles Rhône 3– From the Rhône to Wansdyke

Britain’s Dykes and Waterways: Built for Boats?

One of the strongest pieces of evidence supporting the canal hypothesis lies in the geography of Britain itself. Much of the island’s landscape is hilly and fed by abundant natural springs, particularly at higher elevations. These springs would have provided a consistent water source at altitude, ideal for feeding manmade waterways through gravity alone.

Now consider this: many quarries and prehistoric stone sources are found at the tops of hills. Flat-bottomed barges like the Arles Rhône 3, when used in this context, make perfect engineering sense. They could be dragged uphill while empty—a task made easier by constructing a large earthen bank or causeway—and then floated downhill fully loaded, using gravity and spring-fed water flow to move cargo efficiently.

This system would eliminate the need for locks or complex water-lifting infrastructure. The consistent gradient and the known spring-fed terrain match perfectly with this form of gravity-assisted water transport. It fits so well with the physical structure of earthworks like Wansdyke and the Vallum that it goes a long way to support the idea that these were never just boundaries or defensive moats—they were engineered canals, tailored for one-way barge traffic designed for the landscape.

Now let’s look at Britain. The Car Dyke, Wansdyke, and Vallum are long, linear earthworks that resemble canals more than fortifications. They run through low-lying, sloping terrain, have consistent gradients, and in many cases, align with rivers and spring sources. (Rhône to Wansdyke).

These are precisely the conditions that suit flat-bottomed barges like the Arles Rhône 3:

  • Shallow water: ✔️
  • Gentle gradients: ✔️
  • Cargo transport potential: ✔️
  • Limited need for locks: ✔️

If the Romans were using this design in Gaul and the Rhine, why wouldn’t they use the same boats in Britain’s engineered water routes?

Even more compelling—what if these British earthworks predate Roman occupation, and the Romans simply inherited them, just as they did the boat design?

From the Rhône to Wansdyke
Arles Rhône 3– From the Rhône to Wansdyke

The Logic of a Pan-European Canal Culture

Flat-bottomed barges are functionally inevitable in any society using water transport through shallow inland terrain. If Gauls had them before the Romans, and Romans used them everywhere from the Rhône to the Po, there’s every reason to think that prehistoric Britons used them too.

Perhaps the real question isn’t whether Roman barges came to Britain—but whether Britain’s prehistoric canal system inspired the very model the Romans used elsewhere. (Rhône to Wansdyke).


Arles Rhône 3: Evidence of One-Way Flow Design

🔻 1. Hull Design: One-Way Flow Bias
The flat-bottomed hull is ideal for shallow, slow-moving water.

But crucially: this shape is not suited to sailing upstream—especially in rivers with even modest currents.

The boat’s structure lacks features (like a deep keel or robust rigging) needed to tack against the flow—meaning it could go downstream easily, but upstream only with assistance.

🐂 2. Towpaths and Towing Evidence
Roman documents (like those by Pliny the Elder) describe towpaths along rivers and canals.

In many parts of the empire (e.g. the Moselle, Po, Tiber, Rhône), goods were floated downstream, and barges were then dragged back by animals or slaves.

Archaeological traces of towpaths—flattened, eroded soil tracks along riverbanks—appear alongside known Roman transport routes.

🔄 3. Wear Patterns and Construction
The wear on the hull of Arles Rhône 3 is consistent with slow, controlled navigation, not being battered by surf or fast-moving water.

Its broad beam and robust timber joinery would have made it sturdy under lateral stress—ideal for being dragged when empty.

📦 4. Transport Economics: Gravity Efficiency
Roman freight economics favoured downhill bulk movement (grains, wine, amphorae) from inland settlements toward ports like Arles, where goods could be offloaded to sea vessels.

It was far more efficient to send heavy goods downstream and then haul the empty barge back uphill.

Example: A full barge might carry 15–30 tonnes of goods downstream, but return empty or lightly loaded—making overland or riverbank hauling feasible.

🧾 5. Roman Textual Support
The Codex Theodosianus and other Roman records refer to barge haulers (tractores or halatores) as part of commercial operations.

Writings from the late Empire reference teams of oxen or slaves towing barges upstream, including detailed provisions for how and when they were paid or taxed.

🏞️ 6. Rhône Geography
The Rhône is a strongly flowing river—even today.

Before modern locks and dams, upstream sailing was nearly impossible for heavy vessels.

Barges like Arles Rhône 3 were almost certainly floated downstream from Roman workshops or upriver loading points, then dragged back to repeat the cycle.

🧠 Conclusion:
They put the pieces together logically:

  • The design says “downstream floater.”
  • The Roman transport economy says “drag it back up.”
  • The archaeological context shows towpath-compatible riverbanks.
  • The written sources say “yes, we hauled stuff.”

So the idea that Arles Rhône 3 and its ilk were floated with gravity and hauled by muscle is not just theory—it’s a conclusion based on design pragmatism, textual evidence, and site context. (Rhône to Wansdyke).


Reclaiming the Narrative

The Arles Rhône 3 doesn’t just tell us about Roman logistics. It gives us a template for understanding the practicality of prehistoric British water transport.

Roman or not, the boat’s design proves one thing: if you have a canal, you need a barge like this. And if Britain has thousands of kilometres of mysterious linear earthworks designed for water—then we know exactly what kind of boat would have sailed through them.

It’s time to stop calling them ditches and start recognising them for what they may truly be: the ancient motorways of a forgotten seafaring civilisation. (Rhône to Wansdyke).

Conclusion: Britain’s Ancient Canal Network

The investigations into Offa’s Dyke, Wansdyke, Car Dyke, and the Vallum strongly suggest that these monumental earthworks were not simply defensive barriers or boundary markers. Instead, the evidence points towards a more sophisticated understanding of their purpose: they were integral components of a vast prehistoric (and later Roman-utilized) network of canals designed for water management and the efficient transportation of goods, particularly quarried materials, across a landscape significantly shaped by higher post-glacial river levels.

By embracing modern technologies like LiDAR and shedding outdated assumptions, we are beginning to unravel the true nature of these enigmatic structures, revealing a prehistoric Britain far more interconnected and technologically capable than previously imagined. The story of these giant waterways is still unfolding, promising further groundbreaking discoveries that will continue to reshape our understanding of Britain’s ancient past.

(Britain's Giant Prehistoric Waterways)
Car Dyke at the edge of the prehistoric flood plain – (Britain’s Giant Prehistoric Waterways)

Timeline of Main Events:

  • Prehistoric Era (before written records):
  • Palaeolithic and Mesolithic Periods: Evidence of human activity and settlements. (Hosfield et al., 2008; various mentions in “DAWN of the LOST CIVILISATION”, “Echoes of Atlantis”)
  • Last Eurasian Ice Sheets: Recession of ice sheets occurred within the last 20,000 years, a relatively recent period geologically. (Hughes et al., 2016)
  • Doggerland: Existence of a landmass connecting the British Isles to mainland Europe in the North Sea. (III, V, 99, various mentions in “DAWN of the LOST CIVILISATION”)
  • Neolithic Period: Construction of ditches and dykes. (Figure 57 in “Enigma”)
  • Construction of Ancient Monuments: Building of Long Barrows, Durrington Walls, Stonehenge, Silbury Hill, Windmill Hill, and other prehistoric sites. Dating evidence suggests activity in the millennia BCE. (Various mentions in “DAWN of the LOST CIVILISATION”, “Enigma”, “The Stonehenge Hoax”)
  • Early Use of Dykes/Canals: Evidence suggesting prehistoric dykes were utilized as waterways or for water management. (Various mentions in “Prehistoric Dykes (Canals) – Offa’s Dyke”, “Prehistoric Dykes (Canals) – Wansdyke”)
  • Bronze Age: Mention of a Bronze Age civilization that sailed the planet, possibly referencing Doggerland. (Jul 17, 2022 Facebook Text)
  • Development of the Word “Dyke”: Evolved from Proto-Indo-European roots to Proto-Germanic (c. 1500–500 BCE) with the dual meaning of “ditch” and “embankment.” (Facebook Texts)
  • Roman Period (c. 43 AD – 410 AD):
  • Roman Chronicler Tacitus (c. 56 AD – c. 120 AD): Mentions the Batavi piercing dikes to flood their land in AD 70. (“Dykes Ditches and Earthwortks”)
  • Roman Activity in Britain: Reworking of prehistoric structures like Wansdyke. (“Prehistoric Dykes (Canals) – Wansdyke”)
  • Construction of Roman Roads: Mention of a possibly “impossible” Roman road to Bath at Old Sarum. (Figure 66 in “Enigma”)
  • Great Chesters Roman Aqueduct: Construction and later questioning of its true nature and connection to local dykes. (“Great Chesters Roman Aqueduct”)
  • Hadrian’s Wall and Vallum: Construction and later re-evaluation of the Vallum’s purpose, suggesting it might have functioned as a water-filled ditch (moat) connected to existing dykes. (“The Hadrian’s Wall Hoax”)
  • Use of Jet: Evidence of Roman mining and manufacturing of Jet in Whitby. (“Prehistoric Dykes (Canals) – Wansdyke”)
  • Post-Roman Period:
  • Old English and Old Norse (c. 500 – 1100 CE): The word “dic” (Old English) and “dík” (Old Norse) were in use, meaning both trench and earthwork. (Facebook Texts)
  • Offa’s Dyke (generally attributed to the 8th century AD): Construction of a significant linear earthwork, potentially utilizing earlier prehistoric structures. (Various mentions in “Prehistoric Dykes (Canals) – Offa’s Dyke”, Robert John Langdon’s quote in “Great Chesters Roman Aqueduct”)
  • Medieval Period:
  • Dikes in the Netherlands (from 12th century onwards): Well-attested construction of dikes, with the Westfriese Omringdijk completed by 1250. (“Dykes Ditches and Earthwortks”)
  • Later Periods:
  • Antiquarian Studies: Individuals like Cunnington and Stukeley map and excavate ancient sites, including dykes. (Figure 59 and 98 in “Enigma”)
  • Modern Archaeological and Geological Research: Utilizing LiDAR and other technologies to re-examine the purpose and origins of ancient earthworks. (Various mentions across sources)

Cast of Characters:

  • Robert John Langdon: A modern-day individual living in West Wales and author of books in the trilogy “Prehistoric Britain,” including “The Post-Glacial Flooding Hypothesis.” He appears to be independently researching and writing about prehistoric Britain.
  • Tacitus: A Roman historian (c. 56 AD – c. 120 AD) who chronicled events in the Roman Empire, including mentioning the Batavi piercing dikes.
  • Offa: An 8th-century King of Mercia, generally credited with the construction of Offa’s Dyke, though the sources suggest possible prehistoric origins or influence.
  • Cunnington: Likely refers to William Cunnington (1754–1810) or his descendants (like Maud Cunnington), early antiquarians who conducted excavations at sites like Woodhenge and Avebury. His excavation plan is mentioned.
  • Stukeley: Likely refers to William Stukeley (1687–1765), an English antiquarian who made detailed surveys and drawings of Stonehenge and other ancient monuments, including Roman roads. His map is mentioned.
  • Pitt-Rivers: Likely refers to Augustus Pitt Rivers (1827–1900), an English archaeologist and ethnologist known for his meticulous excavations, including work on Wansdyke. His cross-section of Wansdyke is mentioned.
  • Harold St. George Grey: An archaeologist who conducted excavations at Avebury and other sites. His sketch of an excavation is mentioned.
  • Hawley: Likely refers to Robert Sibbald Hawley (1850–1932), an archaeologist who conducted significant early excavations at Stonehenge. His discovery of an antler pick is mentioned.
  • Fox: Likely refers to Cyril Fred Fox (1882–1967), a prominent archaeologist who extensively studied Offa’s Dyke. His interpretations of the dyke’s changes in direction are mentioned.
  • Erskine: An archaeologist involved in studying Wansdyke in the 1990s, mentioned in the context of excavation findings.
  • Green: An archaeologist involved in studying Wansdyke in 1966, mentioned in the context of excavation findings.
  • Sheppard: An individual associated with a location on Wansdyke where Pitt Rivers excavated.
  • Isaac Newton: A famous physicist mentioned in the context of individuals whose ideas changed the world, although not directly related to the prehistoric or Roman periods discussed in detail regarding dykes and earthworks.
  • Wilkinson, I. P., Brayson, J., Evans D.J.; Hosfield, Rob & Straker, V. & Gardiner, P. & Brown, Tony & Davies, P. & Fyfe, Ralph & Jones, J. & Tinsley, H.; Hughes, A. L. C., Gyllencreutz, R., Lohne, Ø. S., Mangerud, J., Svendsen, J. I.: Authors of the academic papers cited regarding geological and archaeological contexts.
  • Robert John Langdon: A modern author (2023) who has questioned the conventional understanding of Offa’s Dyke and other earthworks.

This timeline and cast provide a structured overview of the information presented in the provided sources. The sources heavily focus on the origins, purpose, and reinterpretation of ancient earthworks, particularly dykes, in the British Isles, spanning from prehistoric times through the Roman period and up to modern archaeological investigations.

Further Reading

For those interested in British Prehistory, visit www.prehistoric-britain.co.uk, a comprehensive resource featuring an extensive collection of archaeology articles, modern LiDAR investigations, and groundbreaking research. The site also includes insights and extracts from the acclaimed Robert John Langdon Trilogy, a series of books exploring Britain during the Prehistoric period. Titles in the trilogy include The Stonehenge Enigma, Dawn of the Lost Civilisation, and The Post Glacial Flooding Hypothesis, offering compelling evidence about ancient landscapes shaped by post-glacial flooding.

To further explore these topics, Robert John Langdon has developed a dedicated YouTube channel featuring over 100 video documentaries and investigations that complement the trilogy. Notable discoveries and studies showcased on the channel include 13 Things that Don’t Make Sense in History and the revelation of Silbury Avenue – The Lost Stone Avenue, a rediscovered prehistoric feature at Avebury, Wiltshire.

In addition to his main works, Langdon has released a series of shorter, accessible publications, ideal for readers delving into specific topics. These include:

For active discussions and updates on the trilogy’s findings and recent LiDAR investigations, join our vibrant community on Facebook. Engage with like-minded enthusiasts by leaving a message or contributing to debates in our Facebook Group.

Whether through the books, the website, or interactive videos, we aim to provide a deeper understanding of Britain’s fascinating prehistoric past. We encourage you to explore these resources and uncover the mysteries of ancient landscapes through the lens of modern archaeology.

For more information, including chapter extracts and related publications, visit the Robert John Langdon Author Page. Dive into works such as The Stonehenge Enigma or Dawn of the Lost Civilisation, and explore cutting-edge theories that challenge traditional historical narratives.(Blackhenge: Debunking the Media misinterpretation of the Stonehenge Builders)


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