Something like three-quarters of the River Thames is not in London. Head west, and the river meanders through Windsor, Marlow, Henley, Reading and Oxford. Keep heading west and you'll eventually reach parts where the Thames is a mere trickle. But where does it begin?
There are numerous candidates, but the two most popular are both in Gloucestershire. We visited them both.
"It's over there. You can't miss it. But it's very underwhelming."
So warns a fellow pilgrim who's made the trek out to Trewsbury Mead, southwest of Cirencester, in search of the Thames headwater. He has a point. The hole from which London's great river springs is drier than the track we used to get here. You can only see it following heavy rain.
Nevertheless, this remote field has long held the accolade as the source of the Thames. You'll find it marked on the Ordnance Survey maps, cited in reference books and even marked on Google Maps with a cultural pin. As long ago as 1546, the scholar John Leland declared Trewsbury Mead as the source, and most authorities have agreed with him since.
This source has even had divine support. From 1958 to 1974, a statue of Old Father Thames graced this meadow. The reclining river god was originally commissioned for the grounds of Crystal Palace, but was later shifted to this field in Gloucestershire. It has since been moved to St John's Lock near Lechlade.
Today, the site is marked by a rather grand stone whose inscription is just about readable, if not photographable:
THE CONSERVATORS OF THE RIVER THAMES
THIS STONE WAS PLACED HERE TO MARK THE
SOURCE OF THE RIVER THAMES
The 'Conservators of the River Thames', also known as the Thames Conservancy, was the body which managed this section of river between the dates shown.
The spring itself is marked by a ring of stones. Dry during our visit, it does flow impressively after heavy rain, as numerous photographs online attest. The only other feature is a Thames Path sign post, which offers daunting news to anyone thinking of walking from source to sea.
Unable to get our feet wet, we trudged off to a more reliable watering hole, the Thames Head Inn, half a mile away. Its pub sign features the Old Father Thames statue mentioned above.
Trewsbury Mead might be the traditional source, but there's a much more convincing candidate 11 miles away towards Cheltenham.
You'll find it beside a handy layby on the A436, in a small hamlet known (for reasons you can guess) as Seven Springs.
Here, down some steps in a small dell, seven trickles of water fall into a pool. These natural springs are the source of the River Churn, a tributary of the Thames.
Seven Springs is in water all year round, unlike the dry ground we saw at Trewsbury Mead. We couldn't resist a paddle in these most up-stream Thames waters.
A sign nearby makes an irresolute claim in mossy Latin:
'Hic tuus o Tamesine Pater septemceminus fons' translates as 'Here, O Father Thames, is your sevenfold spring'. Notice that it's not claiming to be the ultimate source, merely a seven-fold spring that feeds the Thames.
The local council has erected a less poetic, but more informative notice. Handlily, this one's written in a language we can all understand.
As the sign points out, if we include the Churn as part of the Thames, then we add 14 miles to the length of the river. This would make it longer than the Severn, and therefore the longest river in the UK.
And why not? Seven Springs is also at higher elevation than Trewsbury Mead (210 metres versus 110 metres). According to Wikipedia (and other sites), 'Where a river is fed by more than one source, it is usual to regard the highest as its source'. So by all rights, Seven Springs should be considered the true origin of the Thames, with the branch to Trewsbury relegated to a tributary.
It's hard to argue against 500 years of tradition, but we can't help siding with Seven Springs. It's further from the sea and further west, it's at higher elevation, it's good for a paddle... and it even has its own burger van. Still, we can't see the 'official' source ever losing its status. As an old rhyme asserts:
The best of authorities, all are agreed
The source of the Thames is in Trewsbury Mead!
All images by the author, except the lower map, (c) Illustrated London News, courtesy of the British Newspaper Archive.