25 The Lost Rivers of London

Faculty Mentor: Isabel Moreira (History, University of Utah)

The lost rivers of London have always been of great interest to scholars across many disciplines including history, archeology, and geography for the insight they can provide about times that have long since passed. For historians specifically, studying lost rivers and their surroundings can bridge gaps in our knowledge about topics such as urban development, infrastructure, trade, social culture, and effects of environmental factors on a city and its people. Until relatively recently, much of the early research regarding the locations of lost rivers and their contributions to society has been primarily based on written sources. Over the last two decades, a team of geoarcheologists working with the Museum of London Archaeology (MOLA) have taken advantage of expansions being done across Westminster by implementing innovative geoarcheology techniques at construction sites, allowing them to expand on the existing research about lost rivers of London. As an act of “educational charity” MOLA has published their key findings using an ArcGIS StoryMap, walking us through the ancient Tyburn River valley.[1] The project is ongoing, but the findings they have made so far offer historians a window into the landscape of medieval London.

While construction for expansions and restoration around Westminster seems like nothing more than an inconvenience for Londoners, for geoarcheologists it offers an invaluable opportunity to examine what lies beneath the city’s surface. In the course of searching for the lost Tyburn River, a tributary of the Thames River,[2] the team of specialists working with MOLA visited sites all over the city, most often construction sites, to collect earth samples from bore holes and trenches for analysis. Borehole samples are collected by drilling into the earth and extracting a section, keeping the layers intact for further analysis. The trenches however are more consistent with traditional archeology trenches, exposing a large section of earth beneath the surface, allowing for more in-depth analysis at the site. Once the samples have been collected the location of each one is logged on a map to ensure any data extracted can be geographically placed when creating maps following the analysis of ancient deposits within each sample. Once a sample is logged, the layers of sand, clay, peat, silt, and mud are analyzed for ancient sediments that provide environmental and temporal information about the location from which it was collected. In addition to the sedentary information, MOLA specialists also look at known flora and fauna evidence confirmed in the area (such as pollen spores and inspect remains) compared to those in the samples for further information about environment factors of the area.

Based on the data gathered from over 4,000 samples contributing to the research of the Tyburn River,[3] the team of researchers input their findings into a computer modeling system that is able to construct a rendering of the Westminster area (found on the StoryMap), indicating which areas were likely to be low-lying wetlands versus those that were likely higher dry ground.[4] After constructing a model of the Tyburn River floodplains in London, researchers were then able to approximate where the river, and its theorized branches, once flowed. There is much scholarly debate surrounding the potential routes of the Tyburn River, however information collected from this research continues to shed light on those debates. According to collected data and the topographical rendering of the floodplains, the team of geoarcheologists was able to produce three potential routes of the Tyburn River. The first theorized route is that the Tyburn River flowed east across London into Westminster where it split into two branches forming what used to be Thorney Island. The second theory is that the river simply flowed south through the city into the River Thames. The third theory is that both of these proposed branches of the Tyburn River existed together. Remarkably these suggested courses for the river are consistent with those of Nicholas Barton, a leading scholar in the study of London’s lost rivers. In his book “The Lost Rivers of London” Barton examines in great detail, written sources from the eighth century onward, to construct his own image of what London’s landscape once looked like before its rivers were lost. In Chapter 3 of Barton’s book discussing the Tyburn River, he looks to charters, like those of Offa (c.785) and Edgar (c. 951), correspondences from Londoners that mention the river with other commonly known landmarks, earlier geological evidence, and early maps of the area like that of Norden (c. 1593).[5] Barton’s work is considered one of the most influential treatises on the subject, however it is lacking corporeal evidence. The work of MOLA has offered an invaluable extension to the work of Barton, complementing his research rather than seeking to disprove it.

One of the city’s development sites used by researchers for the MOLA project was Victoria Circle to the north of Victoria Underground Station, where the team collected samples from boreholes and trenches to expand their data and understanding of the Tyburn River floodplain. At this site, geoarcheologists designated five facies[6] based on macroscopic characteristics of the borehole samples and trenches. The fifth facies was used to denote anything post c. 1000 BCE. In Trench 5 there was charred matter which, after radiocarbon dating, appeared to be from the late thirteenth to fourteenth century. Along with the carbon dated material, experts conducted a pollen report[7] from the samples in Trench 5 that indicated a decrease in pollen from certain plants, thus indicating there was an increase of grain crops in the general area after the early medieval period. Despite the pollen record indicating an increase of grain crops nearby, researchers were also able to conclude that this immediate area surrounding Trench 5 was likely a wetland during the Middle Ages, unviable for building houses or farming due to frequent flooding.[8]

The Tyburn River is not the only river of interest, there are dozens of other lost rivers across London that are of great interest to scholars from many disciplines. In Barton’s book he takes great care to discuss many of the more well-known rivers such as the Walbrook River, the Fleet River, and the Lea River.[9] Through MOLA’s efforts at another excavation site on High Street, in a patch of unused industrial land along the river,[10] geoarcheologists have been able to expand our knowledge about the uses of lost rivers, not just their locations. The Lea River in the Middle Ages was considered the boundary between two neighborhoods, one being Essex where the manor of Hamme (Ham) was situated. Within Ham there are records of eight mills that would have most likely been built along the Lea River or one of its channels, with one being the Saynes Mill. This was a tidal mill originally used for processing grains and was one of the furthest mills from the Thames River.[11] The first recorded mention of Saynes Mill, documenting the lease of the mill, is dated from the thirteenth century. Throughout the thirteenth and fourteenth centuries there are many similar sources documenting the lease and ownership of Saynes Mill. Use of Saynes Mill persisted throughout later centuries with the addition of another mill, a mill house, and a pump house in the sixteenth through eighteenth centuries. Despite much of the archeological evidence from this site being post-medieval, examining the site provides an in-depth understanding of the city’s geography as well as its infrastructure.

As discussed by Derek Keene, the Great Conduit, also uncovered by the MOLA team, was an important place for the social culture and economy of medieval London much like the Tyburn River. It was built sometime in the mid-thirteenth century as a source of water for those living in the area and was considered a monumental structure. There are many contemporary written sources mentioning the conduit, as early as the late thirteenth century, but until it was uncovered, only so many questions could be answered by them.[12] Through uncovering the conduit, researchers not only get a sense for the location of an important water source, but also the location of social gatherings and events such as pageants. Uncovering the Great Conduit also provides a lot of insight into the level of engineering and infrastructure that was used in the Middle Ages. There are written sources attesting to how it was built, but to physically examine the structure provides a far more intimate understanding of history. Much like the conduit, rivers have a wealth of insight to share with those who know how to find them. Rivers were, and still are, an important element when planning a city. They were at the core of the engineering and infrastructure, they provided the water for everyone whether it be directly or through diversion to a well, and they were a place of social importance whether it be for recreation or to witness a trial.

In a city like London that was, and still is, at the center of the world, there are centuries, even millenniums, of history that have been built over and are yet to be found. Because the centuries of building and expanding never slowed, it is difficult and oftentimes impossible to know what lies beneath. Lost rivers are one of the many things that could provide invaluable insight into London’s profound history, if only they were accessible. The work of MOLA, especially in taking advantage of construction sites, has allowed research to be shared with scholars across all disciplines, illuminating history before it vanishes. Finding lost rivers can tell us which areas of the city were fit for building, or not, making it more feasible to locate cities. Knowing where a city or even a small village once was is important for not only a deeper understanding of the medieval world, but also for knowing where to look for further archeological evidence.

Endnotes

1. Virgil Yendell. “London’s Lost River: The Tyburn.” Accessed April 12, 2023. https://www.arcgis.com/apps/Cascade/index.html?appid=6b00daa1acac4df7a2fcde06104bac1a.
2. A tributary is a river or stream that flows into a larger river or lake.
3. Virgil Yendell. “Liberating the Once Carefree Wanderer: The River Tyburn at the Curtis Green Building, Victoria Embankment, Westminster.” London Archaeologist. 131.
4. Yendell, Virgil. “London’s Lost River: The Tyburn.”
5. Nicholas Barton. The Lost Rivers of London. London: Historical Publications Ltd, 1992. 34-42.
6. A facies is the observable characteristics and changes of a body of rock such as its formation, composition, and fossil content that make it distinct from other areas which can be used for dating bodies of rock.
7. A pollen report is an analysis of pollen preserved in sediment or fossils that have been dated to provide information about past ecological systems.
8. Yendell and Scaife, “Invisible people next to a river that does not exist: geoarchaeology and the Tyburn River north of Victoria Station,” 32.
9. Nicholas Barton. The Lost Rivers of London. London: Historical Publications Ltd, 1992
10. MOLA Team. “150 Strarford High Street,” 2008. https://www.mola.org.uk/blog/150-stratford-high-street.
11. Wroe-Brown, Robin, Ian Betts, Lyn Blackmore, Damian Goodburn, Bob Spain, Geoff Egan, Jackie Keily, and Jacqui Pearce. “Saynes Mill: Excavation of a Tide Mill on the River Lea, London.” Post-Medieval Archaeology. 357.
12. Derek Keene. “Issues of Water in Medieval London to c. 1300.” Urban History 28, no. 2 (2001): 176.