First Footprints: Bronze Age and Iron Age Portsea Island – Early History of Portsmouth

When you stand on Southsea seafront and look out across the Solent, it’s easy to think Portsmouth’s story begins with forts, frigates and the Royal Navy. In reality, people were using this landscape thousands of years before anyone dreamt of a dockyard and long before “Portsmouth” existed as an idea.

In Week 1, we looked at the drowned valleys and Ice Age rivers that shaped the Solent. This week, we jump forward into the Bronze Age and Iron Age, when the first clear human fingerprints appear around what would become Portsea Island.

A changing island: from dry land to tidal world

By the Bronze Age (around 2200–800 BC) and Iron Age (roughly 750 BC–AD 43), rising sea levels had transformed this corner of Hampshire. What had once been a low, marshy river valley was becoming the familiar pattern of islands, creeks and salt marsh.

A Portsmouth landscape study notes that by the later prehistoric period, the Portsea area had developed into salt marsh, small islands and “tributary” tidal rivers, with sea levels approaching what we recognise today by the end of the Iron Age.

In simple terms:

• The high ground of Portsdown Hill remained solid, dry land.

• To the south, the low-lying area that would become Portsea Island was increasingly cut off by tidal channels.

• Langstone Harbour and the eastern shore became a watery maze – tricky for farming, perfect for grazing, fishing and travel by boat.

Portsea Island, as we know it, an island city, is really a Bronze Age and Iron Age creation, born from this long, slow flooding.

Bronze Age Portsea: hoards, harbours and hidden paths

So who was actually here?

We don’t (yet) have a picture of big Bronze Age villages on Portsea itself, but we do have some tantalising evidence that people were moving through, working and perhaps ritualising this landscape.

Bronze hoards near the heart of modern Portsmouth

Archaeological work has recorded two Bronze Age hoards of metal objects to the north-east of the historic town centre, in the area between St Mary’s Hospital and St James’ Hospital.

These were buried collections of bronze artefacts, the sort of thing people might hide for safekeeping, offer to the gods, or store as scrap metal ready to be melted down.

We don’t know who put them there, or why, but it tells us:

• People were active on Portsea’s higher, drier patches well over 3,000 years ago.

• Metalworkers, traders or ritual specialists were moving along this corridor between the harbour and the mainland.

The next time you pass that part of town, it’s worth remembering: beneath the tarmac and tower blocks, someone once buried a stash of prized Bronze Age kit.

Langstone Harbour: a prehistoric service station

Most of the clear Bronze Age finds cluster around Langstone Harbour and Farlington Marshes. Excavations and shoreline surveys have recovered Bronze Age pottery, cremation urns and other material from the harbour’s islands and mudflats.

Archaeologists think that by this time:

• Permanent settlement and burial mounds (barrows) were on the slightly higher coastal plain.

• The harbour fringe – including what would become eastern Portsea – was ideal for summer grazing, fishing, fowling and crossing from island to island.

Imagine small boats slipping through the creeks where the Eastern Road now runs, herders bringing cattle out onto the marsh in the warmer months, and travellers using the harbour as a watery highway between communities.

Iron Age horizons: fields on the high ground, creeks below

Moving into the Iron Age (around 750 BC to the Roman conquest in AD 43), the wider Portsmouth area starts to look more familiar in archaeological terms.

Across southern Britain, this was the age of:

• Iron tools – tougher ploughs, axes and blades that changed farming and woodland management.

• Enclosed settlements and field systems, with landscapes divided into plots for crops and pasture.

• In some regions, hillforts and defended enclosures, though their exact purpose is still debated.

In the Portsmouth area, the densest evidence sits just off the island:

• The city’s heritage strategy notes Neolithic and Iron Age archaeology on and around Portsdown Hill – the high ridge overlooking Portsea and the harbours below.

• Iron Age agricultural features have been found on Portsdown and nearby sites, suggesting mixed farming communities looking down over the tidal inlets.

From those slopes, you’d have had a superb view of the developing harbour network – and a clear route down to what became Portsea Island.

Iron Age Portsea: traces in the marsh

On Portsea Island itself, the Iron Age story is subtle, but it’s there if you know where to look.

Pottery, pits and burnt flints

Archaeological assessments for modern infrastructure – including power cables and road schemes – have picked up Late Bronze Age and Early Iron Age pottery and spreads of burnt flint along the island’s eastern and southern edges, especially towards Farlington Marshes and the Milton area.

These finds hint at:

• Temporary camps or work areas on slightly raised ground in an otherwise marshy zone.

• Activities like cooking, processing food, or working with flint and metal close to the water.

• People used small “islands” within the marsh – the last bits of higher land as sea levels rose.

It’s not the big Iron Age village with roundhouses you might see in a textbook, but it is a clear sign that Portsea’s muddy edges were part of everyday life – a working frontier between land and sea.

What life here might have felt like

Because prehistoric people didn’t leave written records, everything comes down to artefacts, soil layers and a lot of careful inference. But based on regional evidence, we can sketch a likely picture.

Everyday life

• On the higher ground (Portsdown, inland Hampshire):

• Small farming settlements with roundhouses, granaries and paddocks.

• Fields of cereals, herds of cattle, sheep and pigs.

On Portsea and along the harbour edge:

• Seasonal grazing on the salt marsh and rough grassland.

• Fishing, shellfish gathering and possibly early salt-working.

• Boat travel across the harbour network, linking communities on both sides of the water.

Belief and ritual

The Bronze Age hoards near St Mary’s and St James’, and the finds from Langstone Harbour, sit within a wider pattern where water and liminal places (marshes, rivers, inlets) seem to have had special meaning.

Were the hoards hidden savings, ritual offerings, or both? We can’t say for sure, but the choice of location – a low-lying coastal landscape, close to channels and creeks – feels deliberate.

Walking the Bronze Age and Iron Age landscape today

One of the pleasures of living in Portsmouth is that you can step into this story on your lunch break.

A few easy ways to “time travel”:

• Farlington Marshes – Walk the sea wall and imagine the higher patches of ground as Bronze and Iron Age “islets” used for grazing and seasonal camps.

• Eastern Road shoreline – Look across Langstone Harbour and picture it with fewer yachts, more logboats and open water where today you see reclaimed land.

• Milton foreshore & Eastney Lake – At very low tide, the channels and mudflats still show the complicated, braided landscape that prehistoric people navigated.

• Portsdown Hill viewpoint – Stand at the top and look south. You’re roughly sharing the view Iron Age farmers had over the developing harbours and the not-quite-island of Portsea.

None of these places has big visitor centres or replica roundhouses. The archaeology is mostly buried, recorded in reports and museum stores. But once you know it’s there, it’s hard not to feel the deep time beneath your feet.

Why this matters for Portsmouth’s story

The Bronze Age and Iron Age don’t give us “Portsmouth” in name, but they do give us:

• The physical island city, shaped by post-Ice Age sea level rise.

• The first clear evidence of people using and investing in Portsea’s landscape includes burying metal, grazing animals, and working along the creeks.

• A network of harbour routes and coastal communities that later societies, Roman, Saxon, and medieval, would build upon.

By the time the Romans arrived, the basic stage was set: a sheltered stretch of water, a tidal island at its heart, and generations of people already familiar with using this place as a crossroads between land and sea.

In Week 3, we’ll follow that thread forward and explore how the Roman world interacted with this quietly busy corner of the Solent – and how Portsea’s marshy edges began their long transformation towards a fortified, bustling port.