An evaluation commissioned by Connolly Leather to assess any archaeological remains below abandoned allotments enclosed by the northern perimeter of St Mildred's Tannery prior to the proposed redevelopment of the site was carried out in November 1991. The site code was TAN91.

A trench measuring c. 32.65 m by 3.00 m was excavated mechanically in the abandoned allotments. A complex Roman horizon was revealed at the bottom of the trench (at c. 8.00 m OD), beneath only 1.10-1.20 m of later deposits. At the eastern end of the trench a Roman metalled street was found, aligned north-east to south-west, running north to Watling Street but with a marked gradient down towards the east (this was interpreted as probably providing drainage to a sewer or the river Stour). The road had been remetalled on numerous occasions, and had a raised lip on the western side.

To the west of the road, traces of a timber and masonry building or buildings was located, with its eastern side defined by scarring in the road surface that was interpreted as a possible timber ground plate for a wall forming one side of a portico. A floor surface to the west of this was also revealed, with a base of broken tiles which supported a bed of opus signinum overlain by mortar: this was interpreted as the floor of the portico. Beyond the floor bedding was a substantial masonry wall footing <ref 24>, interpreted as the mortared foundations for the other wall of the portico. To the west lay a clay-floored room with a beam scar marking its further wall. West of this room was a roughly metalled courtyard. Beyond the courtyard lay another portico or corridor with a mortar floor, its eastern side defined by a beam slot and its western side by a substantial wall on gravel foundations. A very lightly metalled area west of the building was probably part of a garden or similar open ground.

The building was abandoned in the late Roman period because of a rising water table: its walls had been razed and almost all of the building materials removed from the site. A thick blanket of humus-rich soil developed over the latest Roman horizon. This layer of peat was then overlain by further deposits of dark loam, which contained the remains of numerous wooden stakes and several posts: this was interpreted as evidence for cultivation. The general level was then raised by a series of dumped deposits and the area given over to the allotments within the northern perimeter of the tannery.

Pratt, S., 1993, St Mildred's Tannery (Article in serial). SKE30793.

Pratt, S., 2000, Tannery Evaluation Trench: Proposed Supermarket Site (Unpublished document). SKE30637.