ULAS
University of Leicester Archaeological Services

Merlin Works, Bath Lane, Leicester: The Roman Town Defences and a possible Public Baths Building

ULAS undertook an excavation between July and November 2007 on the site of the former Merlin Dye Works, situated between Bath Lane and the River Soar in the western part of the Roman and medieval town.

The earliest evidence for activity on the site consisted of a significant group of prehistoric flint tools and associated waste production flakes, including Upper Palaeolithic type blades, the first such material ever to be found in Leicester, together with possible Mesolithic material

The area of the excavation fronting Bath Lane produced important evidence for coin production during the transitional late Iron Age/Roman Conquest period.  This took the form of a series of fragmentary clay floors and beam slots and postholes, possibly representing the remains of workshop(s) linked to the production of coin blanks, as evidenced by the discovery of large quantities of fragments of ceramic ‘flan trays’ into which molten gold and silver would have been poured and cast as pellets prior to stamping in a mould to produce coins. The varying sizes of holes in the moulds are likely to reflect the range of coin denominations being produced.

This activity was flanked to the west by a shallow, open U-shaped ditch measuring c.3m wide and c.1m deep and running northwest- southeast across the excavation.  In its earliest phase this is likely to have functioned as the western boundary ditch surrounding the pre-Roman civilian settlement known to have occupied the eastern side of the River Soar

In the later first century AD the area was cleared and an unknown number of timber buildings constructed, indicated by timber beam-slots and associated yellow and green sandy clay floors.  These structures appear to have been short lived, as in either the late first or early second centuries AD they were removed and replaced with a substantial and sizeable masonry building or complex of buildings, work which initially required the dumping of material on the riverward side of the site in order to provide a dry and stable construction base.

The central part of the structure consisted of a roughly rectangular building orientated south-west to north-east with a semi-circular apsidal west end.  A second, smaller apse was attached to the southern wall, and may have been heated via an underfloor hypocaust system.  The central core of the building was flanked to the east by additional rooms and/or structures, and to the north by a possible open courtyard to the north.  The various elements appear to have been linked by an encircling corridor arrangement which was subsequently remodelled in order to create open arcading.  Although the building had sustained considerable damage during the nineteenth century with construction of the dye works, it was clearly a substantial and well-constructed structure whose plan only partially fell within the confines of the excavation.  Nevertheless, its monumental scale and substantial build suggest it having functioned as a public building, possibly an early baths complex.

The western line of the Roman town defences were identified running broadly north-south through the site approximately parallel to the River Soar.  The earth rampart associated with the initial late 2nd or early 3rd century defensive phase overlay the north-west corner of the early Roman apsidal building, the latter apparently demolished in order to allow construction of the earth bank.  Two substantial timber stakes found driven into the river gravels south-east of the apsidal building along with a possible linear cut feature may represent timber revetment of the earth rampart and an associated external defensive ditch.  The 3rd century masonry phase of the town defences was also identified, seemingly ‘dog-legging’ around the western apse of the early Roman building, producing a slight kink in its line.  The wall foundations consisted of substantial unmortared granite fragments positioned at a raked angle within a construction trench, supporting a 6.6m length of surviving standing wall superstructure.  Two substantial fragments of wall masonry lay where they had fallen, one showing external facing stones.  Substantial spreads of granite rubble located beyond the external wall face appeared to represent medieval attempts at land consolidation and/or ground levelling, the material backfilling a cut feature, possibly the external defensive ditch.

The most prominent feature of medieval date was the 1.5m high wall built across the line of the Roman defences, which historic maps suggests as representing the southern boundary of the Blackfriars monastic precinct, known to date to before 1538.  This substantial structure formed a boundary defining two distinctly different sequences of medieval activity.

Firstly, the southern zone was characterised by substantial and dense industrial activity, probably fell mongering – the cleaning of animal skins - in the form of granite-lined tanks set within a crudely metalled yard area; historical records document such a business occupying this area during the eighteenth century.  Records also name this plot of land as Water Laggs and in the ownership of the Austen Friars during the medieval period.

Removal of the tanks and occupational material revealed a sequence of substantial cobbled yard surfaces beginning with a crudely cobbled lane extending west from Friars Causeway/Blackfriars Street towards the river.  This feature may have formed the boundary subsequently used for the setting out of the Blackfriars monastic precinct, the southern wall of which was constructed directly upon this surface.  The yard area to the south of the Blackfriars wall was overlain by a thick accumulation of organically rich material containing considerable quantities of animal bone, including butchery waste.

By contrast, the area north of the wall was characterised by a complete absence of any post-Roman activity, with the notable exception of a possible latrine and associated well and drains, the former consisting of a sizeable square or rectangular feature measuring c.9.50m by 5m.  Excavation revealed it to have a dry stone granite lining and a substantial Roman mortar floor base and to contain medieval pottery and highly organic material.

This would appear to represent a medieval reuse of a Roman feature as a cess pit, and it is possibly linked to a reference in the Leicester borough records to the transfer of land from the Blackfriars monastic community to the corporation for the construction of a communal toilet in 1342/3.  The theory of this having functioned as some form of latrine is supported by a stone-based open drain linking it with a stone lined well c.6m to the east.  It is possible that well water was periodically used to clear the feature.

Dr. Roger Kipling, ULAS Field Officer