Red Sands Sea Forts
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7 Treasures of the Thames Estuary

The Thames Estuary has been the traditional entry point for imports and exports, both human and material, for centuries.

The Thames Estuary, where the North Sea meets the River Thames is a major international shipping route bordered by the counties of Essex and Kent.

It has been the traditional entry point for imports and exports, both human and material, for centuries. The area is dotted with military defences, memorials, shipwrecks and churches that tell a rich and complex history of industry, empire and immigration.

Here are (actually a few more than) 7 historic treasures that help to demystify this great waterway.

1. Boundaries

The London Stone at Upnor reads ‘God protect the City of London’ © Historic England DP113995

The River Thames stretches for over 200 miles from the Cotswolds all the way across London and out to the North Sea. In 1197, King Richard I sold his rights to the lower reaches of the Thames and part of the Medway to the City of London in order to finance his crusades. The City marked out its new jurisdiction with boundary stones: the Crow Stone at Chalkwell in Essex (which you can walk out to at low tide), at Upnor as well as an Obelisk, and another stone on the Isle of Grain.

2. Military defences and factories

Hadleigh Castle, a 13th century ruined fortification in Essex © Historic England DP068097


Grain Tower seen in the distance on a sand bank at low tide
Grain Tower © Historic England DP165044

As the maritime entrance to London, the Thames has always been of great strategic importance and so the estuary was always fortified. Military defences include Hadleigh Castle and Grain Tower, both built as defence against the French in the 13th and 19th Centuries respectively.

Anti-tank obstacles - carved geometric stones - on a beach
Anti-Tank Obstacles, Isle of Grain © Historic England DP076215

Later endeavours include anti-tank obstacles on the Isle of Grain and the striking Red Sands Sea Forts, which were built to provide anti-aircraft fire during the Second World War. Meanwhile Cliffe Marshes is an extensive area of reclaimed estuary salt-marsh and was the site of a Victorian explosives factory that opened in 1892.

maunsell - mark edwards
Red Sands Sea Forts © Mark Edwards – Winner of the Triphistoric Photographer of the Year Awards, English History Category


Former Explosives Factory, Cliffe
Former Explosives Factory, Cliffe, Hoo Peninsula. Kent © Historic England DP141631

3. Shipwrecks

Visible remnants of the SS Montgomery
Visible remnants of the SS Montgomery © Clem Rutter via wikipedia

The Thames Estuary is home to around 767 recorded wrecks: the earliest known are documented from battles recorded in the Anglo-Saxon Chronicle 893-894 and the figure also includes downed aircraft from the Second World War and wrecks of Thames barges.

The London was accidentally blown up in 1665, an incident recorded by Samuel Pepys in his diary. The SS Montgomery sank in 1944 and was designated a dangerous wreck in 1973 on account of the presence of live munitions in the ship: her masts are still visible, as the wreck is at a depth of just under 50ft.

4. Pocahontas

An almost life-size image of Pocahontas, with a feathered headdress, stands atop a plinth that reads 'POCAHONTAS'
St Georges Church, Pocahontas Statue, Gravesend, Kent © Historic England DD002580

In 1606 three ships set sail from Blackwall in London, on board were 105 settlers bound for North America and on arrival they established Jamestown as the first Virginian English colony. In 1616, The Virginia Company of London travelled to England in order to raise funds, bringing with them a Powhatan Native American woman called Pocahontas, who had been converted to Christianity and was married to the English colonist John Rolfe.

The following year as they set sail to return to Jamestown Pocahontas became ill, and was taken ashore at Gravesend in Kent, where she died. Her funeral took place on 21 March 1617 in the parish of St George and though her exact burial place is unknown, a statue in the graveyard remembers her.

5. Early settlers

A small, light pink octagonal cottage with a thatched roof. The painted date above the grey front door reads '1618'
Dutch octagonal cottages © Oneblackline from wikipedia

Located entirely below sea level, the history of Canvey Island has been dictated by the creeks and the Estuary that surround it. In the early 17th century the Dutch engineer Cornelius Vermuyden brought land reclamation methods from the Netherlands to England, to undertake work in the Fens and at Canvey.

With him came Dutch labourers and their families, many of whom settled on the island. Two cottages built by the labourers remain, from 1618 and 1621, both of them listed at Grade II.

6. Life and death on the Estuary

Pip’s Graves, the graves of 13 children who died of marsh fever
Pip’s Graves, the graves of 13 children who died of marsh fever © The Churches Conservation Trust

On the Hoo Peninsula in Kent is the Grade I listed Church of St James at Cooling, which dates from the late 1200s and early 1300s. The desolate landscape and the gravestones of infants, known as ‘Pip’s Graves’ are generally taken to have been the prototypes for the graves detailed on the first page of Charles Dickens’ ‘Great Expectations’.

Exterior of church with gravestones in the foreground
Church of St Mary the Virgin, Foulness Island, Essex. © Martin Newman

Further east and across the water is the Church of Saint Mary the Virgin on Foulness. The remote island is owned by the Ministry of Defence and used for the testing of weapons. It is also home to just under 200 people.

Until the early 20th century, the only access to the island was by a path known as the Broomway, which could only be accessed when the tide was out. In use for at least 600 years, the Broomway extends for six miles and is considered one of the most dangerous paths in England, with over 100 deaths recorded. In the churchyard there are at least 66 burials of those who died attempting to walk it.

7. Tilbury comings and goings

A man on an ocean liner looks on at another moored liner at Tilbury Passenger Landing Stage
Tilbury Passenger Landing Stage, Chadwell St Mary, Thurrock c Historic England Archive AA001371

The Port of Tilbury is the principal port for London, with an annual throughput of 16 million tonnes and its own specialised police force. It opened in 1886 as river trade moved downstream out of central London. Close by is Tilbury Fort, where Elizabeth I gave her famous Speech to the Troops in preparation for an expected invasion by the Spanish Armada.

Men paint a ship's hull at Tilbury Docks
Men paint a ship’s hull at Tilbury Docks, Chadwell St Mary, Thurrock © Historic England Archive AA001614

Tilbury was also London’s passenger liner terminal until the 1960s. It was from here that the ‘Ten Pound Poms’ (white Britons enticed to migrate for just £10) set sail for Australia and New Zealand after the Second World War, and to here that the SS Empire Windrush arrived in 1948 with over 1,000 passengers, the vast majority of them Caribbeans seeking a new life in Britain.

Written by Charlotte Goodhart

Further Reading

13 comments on “7 Treasures of the Thames Estuary

  1. Excellent

  2. Fascinating!

  3. Alison Pick

    Absolutely fascinating. Makes me want to explore the area.

  4. Vince Russett

    The inscribed boundary stone says ‘preserve’ not ‘protect’, I believe (you can see a long ‘s’ in the centre of the word). Interesting stuff, though.

  5. Fascinating history Thank you !!

  6. Roger Ford

    How interesting. Learnt such a lot in a short space of time

  7. Richard Hutchinson

    There was a documentary on abandoned military sites. The Red Sands Forts were anti aircraft gun implacements, offshore and unlit so as to make them invisible to enemy aircraft flying over the sea towards London

  8. This is so interesting I’m planning a trip to the Isle of Grain. A 191 bus from Strood Station will do!

  9. Steve Dudman

    Outstanding. Not from the area but a regular visitor to Tilbury docks as well as most of the Thames ports .

  10. Elizabeth Capewell

    My parents were ten pound poms in 1951 & was only 4 so my passage was free. I have vivid memories if leaving a very grey war torn London and being on the train to London with my grandmother. She’d given me some sweets & I told her I didn’t like them. She died before we came back in 1955 and I always felt guilty about that.
    I also remember the streamers from the boat to those waving goodbye. As the SS Ranchi sailed away the streamers broke. It was so symbolic & heart wrenching.

  11. Christine Punter

    Is there any way of identifying the ship coming in to Tilbury? I left Tilbury with family , emigrating to New Zealand in 1964 on board P & O ship ‘ Himalaya’. Fabulous trip , will never forget it.

  12. For up to date information about the wreck explosives carrier liberty ship SS Richard Montgomery and the dangers it presents to the people of Kent see: The Richard Montgomery matter

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