Medieval Thornborough Bridge is the oldest bridge in the county, but this East to West river crossing is at least 1,200 years older; it dates back to Roman times.
Three Roman roads met and crossed each other here, and by the North side of this six arch medieval bridge over Padbury Brook was a Roman ford, made from limestone blocks held in place with wooden stakes. These were found during excavations in the 1970s.
Also found were three oak pilings on the East bank, and the ends of a road over thirty feet wide on both river banks.
One of these roads came North from Akeman Street (the A41) at Fleet Marston near Aylesbury. Part of it is still used as a road, and it was once part of the old turnpike route to Buckingham. After the river crossing it went through modern Akeley and beyond.
The second road came from what’s now Wolverton, used the crossing, and ended not much further on.
The third road is followed remarkably closely by the modern A421 and B4034, into the heart of Bletchley and along the Queensway. It then meets Watling Street (the A5) near to the canal bridge in Fenny Stratford.
To the West, it doesn’t go all the way to Buckingham but from the brook, heads through Maids Moreton, across Stowe Landscape Gardens, and leaves the county at Biddlesden.
It’s fascinating to see how often lengths of roads or public footpaths or hedges follow the lines of these old roads; sometimes even a road junction can originally be Roman.
The Roman ford was over to the right. You might just be able to see some red retroreflective paint on the edge of the middle refuge.
But what we don’t know is how many of these roads followed even older tracks. The brook just North of the 14th Century bridge is wide and fairly shallow, perhaps thought not too bad for fording, at least in the drier months. But when I visited this week, it was too fast flowing to even consider.
The ford could have been the only easy way to cross the Brook, long before the Romans came.
This was an important place in Roman times. In the field by the bridge are two large burial mounds. Nearby evidence was found of two Roman villas, and to the South was a temple and a cemetary. There was probably a significant settlement here.
The New Bridge
It must have been a great day when the medieval bridge was finally opened, twelve centuries after the Romans built their ford.
The bridge has been repaired in stone and brick over the centuries, but it was originally all stone. There are six arches. The two that take most of the water are more ornate than the rest, with chamfered ribs in their arches.
On the upstream side are three cutwaters, that guide the water and any debris through the arches. At road level, they provide three triangular refuges for pedestrians.
It’s almost as if the two more elaborate arches and the cutwaters either side and between them were built first, and the plainer arches added later, perhaps to replace a temporary wooden causeway.
The Newest Bridge
In 1974 another bridge was built, bypassing the narrow medieval one. Around this time the road was redesignated as the A421. It had been the B4034.
The old bridge still bears scrapes and gouges from when it was in use, despite the reflective paint that’s still visible in places. It’s only about eleven feet wide between the bridge parapets, and that doesn’t leave much clearance when your lorry is eight or more feet across.
Thornborough Bridge is about a quarter of a mile towards Buckingham from the staggered junction for Thornborough and Padbury. There’s plenty of parking and a good information board. It’s well worth a visit and is Grade 1 listed; an ancient monument. The burial mounds, “tumuli”, are worth a look too.
On the other side of the road and about half way back to the staggered junction, is the Twigs Nursery. I haven’t been there, but they do have a coffee shop. It’s open Tuesday to Sunday.
I found much of my information about the Roman roads from the Roman Roads in Britain website; there are detailed maps. I found that one minor Roman road runs through my garden. When I found this out I stood on the path and looked along the direction of the old road, and wondered…