Journey through the deep history of Sidmouth, from Ice Age mammoths and the ancient Oak-Hazel Wildwood to the Saxon salt works of Sedemuda.
When we look across the rolling hills and lush green pastures of the Sid Valley today, it is easy to mistake the landscape for a pristine, "natural" environment. We perceive the British countryside as a timeless tapestry of hedgerows and open fields, yet this familiar vista is a relatively recent development in the context of deep time. Beneath the surface of this idyllic Devon landscape lies a history of radical environmental shifts and massive human engineering. How did a frozen tundra once home to mammoths transform into a dense "wildwood," only to be systematically dismantled by ancient human civilisations? To understand the Sid Valley, we must look past the green and into the profound transformations that shaped its very soil.
To understand the origins of the valley, we must look back 18,000 years to the Late Devensian glaciation. While the massive ice sheets of the last Ice Age generally reached only as far south as the Midlands, Devon was far from a temperate paradise. Instead, it existed as a "periglacial" environment—a frozen, treeless tundra battered by extreme winds.
While no local fossils are buried directly beneath Sidmouth’s streets, we can look to regional proxies at Kent's Cavern and Sherford (near Plymouth) to reconstruct the Sid Valley's prehistoric inhabitants. This was a wilderness of extreme cold, teemed with life that would seem alien to the region today:
Woolly Mammoths
Woolly Rhinoceroses
Hyenas
There is a profound irony in our modern perception of the valley. We often view the current "open" landscape of fields and vistas as the natural state of Devon, yet this openness more closely resembles the harsh, treeless tundra of the Ice Age than the dense primeval forest that followed it. We have, in a sense, returned the valley to a state of exposure that would be familiar to a mammoth, albeit for very different reasons.
As the climate stabilised around 11,500 years ago, the Sid Valley underwent a botanical invasion. The "primeval forest" often depicted in folklore was not a single, static event that appeared overnight; rather, it was a series of successive waves of tree species migrating across the landscape over thousands of years.
As the former tundra warmed, the re-colonisation followed a specific chronological progression:
Pioneer Species (c. 10,000 years ago): Birch and willow were the first to arrive, colonising the landscape from the south and east.
The Second Wave: Pine and hazel followed as the soils began to develop.
The Third Wave: Oak and alder established themselves, particularly in the wetter river lowlands of the Sid.
The Final Arrivals: Lime and elm completed the canopy.
By roughly 5,000 years ago, woodland cover reached its peak. In the Sid Valley, the specific geology dictated the forest’s character. Because Devon’s soils are largely non-calcareous (lacking the lime or chalk found in central England), the "climax state" of the forest settled into what ecologists call the Oak-Hazel model . This reveals that the "natural" forest was a living, shifting entity that took nearly six millennia to reach its peak density.
The open, sweeping views of the Sid Valley that we prize today are not the result of natural processes, but are instead the byproduct of ancient industrial-scale deforestation. The clearing of the dense Wildwood was a monumental undertaking that spanned three distinct technological eras, each bringing more noise and industry to the valley:
The Neolithic (c. 3100–2900 BC): This period saw the first significant, large-scale clearings. Using stone axes, the first farmers began the arduous task of ring-barking trees, leaving them to die standing so that sunlight could reach the first crops of wheat and barley.
The Bronze Age (c. 2500–800 BC): Clearance intensified as settlements pushed from the fertile lowlands up onto higher ground, establishing the first permanent field systems.
The Iron Age (c. 800 BC – AD 43): This era brought the most dramatic transformation. The acrid smoke of ring-barking fires was replaced by the rhythmic clatter of iron axes, which were far more efficient than their predecessors.
The scale of this human intervention is anchored in the local geography. As the historical record suggests:
"The presence of an Iron Age hill fort nearby at Sidbury enforces the likelihood that it was the residents of that fort that cleared the wildwood from the entire Sid valley."
The "open" beauty of the valley is, in reality, a man-made landscape—the result of thousands of years of human ambition and manual labour.
By the 11th century, the Sid Valley was no longer a wild frontier but a strategically divided patchwork of international and local power. The settlement known today as Sidmouth—recorded in the Domesday Book as "Sedemuda" (Old English for "mouth of the Sid")—was a small fishing village with surprisingly global ties.
Before the Norman Conquest of 1066, the valley’s loyalties were split by ecclesiastical law. While the area encompassing Sidbury and Salcombe Regis had been gifted by King Athelstan to Exeter Cathedral, Sidmouth was part of the manor of Otterton. In a remarkable historical twist, Gytha Thorkelsdóttir—the mother of King Harold Godwinson—gifted the Sidmouth land to the Benedictine abbey of Mont-Saint-Michel in Normandy.
This connection was deeply economic. The Domesday Book notes that the Abbey of Mont-Saint-Michel received thirty pence from salt works in "Sedemuda." This early maritime industry linked a small Devon valley directly to the spiritual and political heart of Northern France, showing that even 1,000 years ago, the Sid Valley was an integrated part of the European power structure.
The history of the Sid Valley is a narrative of constant flux. From the frozen tundra of the mammoth to the dense canopy of the Oak-Hazel wildwood, and finally to the cleared agricultural landscape of the Iron Age and the medieval salt trade, the environment has been continuously reshaped by both shifting climates and human industry.
As we walk through the valley today, we are walking through a landscape that has been "constructed" by generations of residents. This invites a compelling question: if the valley has been transformed so radically over the last 10,000 years, what will it look like 10,000 years from now? How will future historians interpret the marks we are leaving on the land today?
Before you go:
Objective: To identify the visible markers of different historical eras—from the Ice Age to the Saxons—within a single view of the Sid Valley (or your local equivalent).
Equipment Needed:
A high vantage point (e.g., a hill overlooking the valley).
A camera or a sketchbook.
A local map (physical or digital).
Phase 1: Identifying the Topography (Ice Age Clues)
Look at the shape of the valley itself.
The V-Shape: Notice how the River Sid has carved the valley. This process was accelerated by the massive "spring melts" at the end of the Ice Age.
The Plateaus: Look at the flat tops of the hills. During the periglacial period, these were frozen tundra where mammoths once roamed.
Sketch/Photo: Take a wide-angle shot and label the "Tundra Plateaus" and the "Meltwater Valley."
Phase 2: Spotting the "Great Clearing" (Iron Age Clues)
Scan the horizons for the highest points in the landscape.
Hill Fort Hunting: Find Sidbury Hill. Imagine it without its modern trees. In the Iron Age, it would have been a bare, fortified crown.
The Tree Line: Look at where the woods are today. Are they on steep slopes that are hard to farm? This shows you exactly where the "Great Clearing" stopped—humans cleared the easy, flat land for crops and left the "wildwood" only on the difficult inclines.
Phase 3: Seeking "Sedemuda" (Saxon Clues)
Move your focus toward the mouth of the river.
The Salt Works: The Domesday Book mentions salt production. This required flat, marshy areas near the sea and plenty of timber for boiling the brine.
The Church Hubs: Find the oldest churches (like St. Giles in Sidbury or the Parish Church in Sidmouth). These often sit on the exact sites of the original Saxon land-holdings gifted by King Athelstan or Gytha.
Fill this in based on your observations from the vantage point:
Era What it looked like then What I can see now
Ice Age Frozen, treeless tundra. The flat hilltops and deep valley floor.
Wildwood Continuous Oak and Hazel forest. Small patches of "remnant" woods on steep hills.
Iron Age Open fields and a busy hill fort. The earthworks of Sidbury Hill.
Saxon Small fishing huts and salt pans. The town centre and river mouth.