The Friends of The Colchester Archaeological Trust


Mercury Theatre update

Since mid November last year, the Trust has been conducting an excavation in the grounds of the Mercury Theatre in Colchester ahead of the construction of two new extensions (the theatre’s ‘Mercury Rising’ scheme). The theatre was built in 1971-2 and it stands on the site of Insula 25a of the Roman town (an insula is an urban block defined by streets), immediately within the Roman town wall. This insula was known to have contained several Roman town-houses and earlier Roman military buildings below these.

CAT’s objective was to uncover the remains of the latest phase of Roman buildings on the site and then help inform the Council’s engineers and architects on the best locations for piles. The use of piles will allow the new extensions to be constructed above the Roman remains, minimising the damage to these important archaeological deposits.

For the most part, we uncovered the plain tessellated floors and wall foundations (or robbed-out foundations) of the latest phase of Roman town-houses on the site. These probably date to the 2nd or 3rd centuries. We have been able to plan the layout of the rooms as well as uncover evidence for the presence of ‘central heating’ in the buildings. During the excavations we have recovered lots of interesting pieces of the buildings themselves, including fragments of beautifully painted wall plaster, as well as a significant number of small finds and many crates of pottery!

Once the visually impressive Roman building remains had been fully recorded, they were covered over again so that they could be preserved indefinitely under the new building. However, before they were covered the locations of the new piles and two new lift shafts were further investigated down to the natural sand so that we could record what would be damaged. During the excavation of the lift-pit for the southern extension, we were very excited to find part of a barrack block wall built by the Roman army around the mid AD40s. Having located one wall, we were then able to measure off of it and uncover two further barrack block walls to the north! This was possible due to the fact the Roman army planned and laid out its bases in standardised patterns defined in terms of Roman feet.

Adam Wightman