Spotlight: Reviving the London Mithraeum
The year is 1954. Post-war rebuilding efforts on Cannon Street have just come to a halt after an archeological discovery becomes one of the most important Roman finds in Great Britain: The London Mithraeum. More than 50 years later, Icon member Spencer Hall ACR and PAYE Conservation working away on the reconstruction of the temple to give it a second life.
With a career spanning over 20 years of conservation in all its forms -- hands-on work, site and project management and even on advisory roles - Spencer Hall ACR can still count the Temple of Mithras in London amongst the most unique projects he’s worked on.
In 2015 his organisation, PAYE Conservation, was invited to contribute to the reconstruction of the site thanks to their experience with projects of a similar size and scale. Spencer’s role was to act as lead liaison between all parties in the workforce, whilst making sure that any necessary compromises in the rebuild would conform to conservation standards and respect as much of the original construction as possible - despite mistakes made in the distant past.
A 1950s discovery
The temple was discovered in 1952, at a time when “conservation as a science was still in its infancy,” according to Spencer. Though initially considered just another archaeological site in the heart of London, a marble bust of the pagan sun god Mithras was unearthed on the last official day of the dig and brought the discovery up to a whole new level. Not only did the bust indicate the ruins were a “Mithraeum” - a rare building dedicated to the ancient Roman deity - but it was also thought to be the most complete example ever found. Dating back to 240 AD, its location had been key in the developing settlement of Londinium.
Finding the bust in 1954 (c) MOLA
“A photographer happened to be present on the day of the find in 1954,” explains Spencer, “and this image made it into The Sunday Times. The dig was extended, and the site opened to the public. A few hundred visitors were expected on day one, but instead thousands arrived. [...] The dig was only granted an extension of 2 weeks but it is felt that within this short period, a reported 400,000 people took the opportunity to visit the site.”
Because of this interest, that year it was decided to renovate the site for ongoing public access. Though steps were taken to maintain the integrity of the building on its reconstruction, the results were less than successful. The head of the excavation project, Professor William Grimes, stated that it was ‘virtually meaningless as a reconstruction of a Mithraeum’.
Temple of Mithras dig 1954. Photo by Robert Hitchman (c) MOLA
Rectifying the mistakes of the past
It would be more than half a century later when the opportunity to remedy this mishap would arise from the site’s purchase for redevelopment.
In order to deliver the project under both tight deadlines and physical spaces, PAYE gathered a large workforce of craftspeople - including traditional stonemasons, plasterers, timber specialists, stone conservators and artists.
Spencer, who specialises in plaster and stone conservation, managed the team of masons and conservators as Project Manager for site work, recording each element as it was assessed and reintroduced into the monument. Also heavily involved with the project were Icon members Catherine Woolfitt ACR, responsible for the production of tender documentation and work standards, and Angus Lawrence ACR of Taylor Pearce.
The material arrives at the workshop (c) PAYE 2015
“The 1960s interpretation used a selection of stones not felt to be contemporary to the original build," says Spencer. "Petrographers were therefore commissioned to review all the existing and asked to identify which elements were true and which were later additions. Following careful examination, approximately 20 pallets of stone were identified and as later additions which needed to be replaced with a material that matched the original.”
“Much of the original brick was lost so in order to try to recreate those lost faithfully, PAYE worked closely with brick makers William Blythe, who produce their bricks in ways that match the processes which would have created the originals used in the temple 2000 years ago."
The masons constructing the Temple (c) PAYE 2016
The wooden elements turned out to be a more complex issue. "A big part of the original timber had survived, being wonderfully preserved in the mud,” Spencer explains, though later admits that due to various circumstances the timber was not retained.
Because of this, the team was forced to recreate much of the woodwork. Thankfully, archival records of the discovery dating back to 1952 included a vast collection of photographs, making the task far more manageable.
“Green English Oak was sourced from a supplier of the South Coast of England in sizable timber widths and cut to approximate size with hand saws. Then began the process of distressing and ageing to give the timber the look of a material that was around 2000 years old and had been freshly excavated.”
The Temple of Mithras is unlike any other project I’ve had the fortune to work on”
Notions of authenticity and a concern for historic accuracy have influenced much of the work - notably on the final touches to create a backdrop for the building.
“To add as much authenticity to this as possible, approximately 3 tonnes of mud and earth were shipped to our warehouse - the material recovered from an adjacent excavation at the same level.”
Applying the silicon rubber to the earthworks to create a mould (c) PAYE 2016
“Pieces of stone, roman brick and oyster shells were not sifted out, but made notable to help authenticate the construction. Once agreement was reached on detail and composition, a silicon rubber was applied to allow the creation of a highly accurate reverse mould. Each cast was interwoven with fibre glass matting, creating solid sections of flooring which even at close quarter are difficult to distinguish from the real thing.”
After more than 2 years of combined efforts to bring the temple back to its original location and former glory, the monument was finally opened to the public on 14 November, 2017. Despite the necessary remake of bricks and timber elements, a large majority of the building pieces are still original, replaced just as they appeared at the end of the excavation in October 1954 under the new Bloomberg European Headquarters building.
The build starts on site (c) PAYE 2016
“The Temple of Mithras is unlike any other project I’ve had the fortune to work on,” says Spencer, who admits that his proudest moment during the project was witnessing the light and sound presentation which accompanies the visitor experience of the temple for the first time.
“In concept it sounded good, but you never quite know how it will actually come across. It has just the right mix of mystical theatre to contextualise the monument perfectly.”
The Temple following the final clean ready for opening (c) PAYE 2017
Find out more about Spencer Hall ACR’s work in his full editorial, to be released in the next edition of Icon News.
Left: People queue to see the temple of Mithras in 1954 (c) MOLA
Right: The Temple following the final clean ready for opening (c) PAYE 2017