Could Roman building lie beneath farm in Harpenden? Student’s data points to possible ‘rare discovery’

Lead researcher Alexander Thomas

Lead researcher Alexander Thomas - Credit: Archant

A Roman industrial building dating between 50AD-400AD could lie beneath the fields of a cattle farm earmarked to be turned into a new secondary school, an investigation has shown.

Alexander Thomas, a PhD student at Bristol University’s department of archaeology and anthropology, has been analysing data from a ground penetrating radar (GPR) survey conducted at Batford Farm, off Common Lane in Harpenden.

What he found had “strong anomalies consistent with a large rectangular building constructed of brick or stone.

Alexander, who grew up in Harpenden, said the rectangular feature on the north side was “not the remains of the [previous] Bonny Boys Farm buildings, as shown in the Tithe and Ordnance Survey maps of the 19th century.

“The majority of the farm buildings would have been destroyed with the extensive widening of Lower Luton Road in the 20th century.”

Alexander said the ‘substantial’ 30m by 15m building was much larger than any of those in the Bonny Boys complex.

The history buff added: “The building is situated further north than Bonny Boys Farm, but to the south of the farm boundary, which can be seen in the 1799 map.

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“An extensive search has been conducted at Hertfordshire Archives to ascertain if there was an earlier brick or stone building in this position in the post-Medieval era. There was not.”

Also, with Bonny Boys Farm and Batford Mill considered a single entity since at least 1658, if there had been a substantial home within the mill and farm complex, “the expectation would be that it would be included in the paper record”.

Alexander said he had concluded that: “The substantial rectangular building made of brick or stone must therefore date to a much earlier period, and the only period in which buildings of this size and shape and in these materials were constructed was the Roman period.”

Although the structure could have been a house, he suggested that, given its location close to the river, the ford, mill and possible pits, and the industrial area which existed in the area in the Roman era, “the building may be a series of workshops or structures designed for trade”.

Alexander added: “If this is the case, then it is very rare discovery, and sheds important light on what was going on in Batford in this period.”

He said that if the structure was a Roman industrial building, work carried out there could be connected to deneholes – chalk extraction pits – discovered in the same GPR survey.

Furthermore, he found evidence of “the existence of a possible shaft which extends down from the entrance of one of the holes.

“This and other circumstantial evidence, such as the pits, suggests there may be tunnels beneath. Mining activity in the immediate area adds weight to the hypothesis that in the pre-Medieval period the area around Batford Mill was a hub of industrial activity. Further investigation is required.”

Alexander said the combination of the survey results and documentary archive “provide compelling evidence to suggest the building remains beneath Batford field are of an early date.”

A spokeswoman for Right School Right Place, a group opposing the development of a new secondary school at the Green Belt site, said the research “confirmed the need for even more detailed work to discover what lies beneath our feet.”

However, Dr Kris Lockyear, a senior lecturer in Archaeology at the Institute of Archaeology, UCL, has pointed out that he has a different interpretation of the data. He helped Alex in undertaking the GPR survey, and wrote a report on it.

The expert said that he and Alex have had to “agree to disagree” over the interpretation of that survey.

He added: “If nothing else, the complete lack of any Roman material culture, for example pottery, brick, roofing tiles, on the surface of that field argues against the presence of any Roman structure whatsoever, let alone some massive industrial building.”

Dr Lockyear said: “The pits are perfectly ordinary chalk pits which are dotted all over the Hertfordshire countryside used to extract chalk for marling, not for any industrial process.

“The presence or otherwise of archaeological remains in this field will not influence the decision about the school, it will just trigger commercial archaeological fieldwork.”

Herts county council cabinet for education, Cllr David Williams, confirmed that Alexander’s findings had been shared with the Education Funding Agency and the Harpenden Secondary Free School “in the expectation that the agency’s contractor will conduct appropriate archaeological field evaluations in due course”.