A Stage 1b (post outline planning consent) trial-trenched evaluation was undertaken by Colchester Archaeological Trust between July and September 2007, comprising 25 trial trenches. Area B1b, 5.2 ha. in size, coincides with the southern and western part of the walled precinct of St John’s Abbey, and with the eastern end of the Roman circus, to the east of Flagstaff Road, Colchester. <1> The evaluation defined evidence for prehistoric, Roman, Medieval and post-medieval activity. A small number of struck flints indicates a low level of activity in the prehistoric period. A large quantity of residual Roman pottery and tile (including tesserae, pila tiles and roofing tiles) is presumably derived from domestic activity and unidentified Roman buildings in this area. Roman pitting is similarly representative of a settlement zone and add to the 2nd century domestic pit found during the 2002 evaluation of the site. Pottery and coin finds suggest a later 1st to 4th century date for this extra-mural occupation. The predicted position of the east end of the Roman circus coincided with the southern edge of the site, and five trenches were specifically targeted on the circus (T23, T26, T27, T28 and T29). These confirmed the expected position of the cavea walls, and also exposed the south face of the partially-robbed St John’s Abbey precinct wall (in T26). One robber trench contained peg-tile, indicating a potentially late date for the end of robbing activity here. A gravel surface was located on the outer side of the circus, matching that previously found on Areas C1 and C2 (ECC2537). <2> Two Roman inhumation burials and one cremation burial, the latter within a large quarry-pit (T31) were excavated at the south end of the site. These were probably part of the same general Roman cemetery previously excavated in GAL Area C2, 150m to the WSW, and at Napier Road, to the south. <4> Loose finds indicate at least three more burials. Roman quarrying was also evident in the south-east corner of the site. Despite the location of this site in the southern and western part of the walled precinct of St John’s Abbey, only one building could definitely be associated with the medieval abbey. This was a right-angled wall foundation with a rough cobble surface on its west side and a clay floor on its east side, possibly the south-west corner of a building with an internal clay floor (in T18). Given the position of this structure, it must have been part of the monastic buildings. Other possibly medieval structural remains were located to the south of the site, on the western edge, where buildings appear to have linked up with the western precinct wall of the abbey. Another abbey-period structure was a lime-kiln/pit (in T17c) possibly contemporary with the rebuilding of the abbey after the major fire of AD 1133. Finds probably from the abbey church include thick glass from a stained-glass window. Other wall foundations containing peg-tile may be late medieval (and so associated with the abbey), or post-medieval and associated with post-Dissolution use of the site and particularly the Lucas mansion. A limited trial-trenched evaluation had previously been undertaken in advance of outline planning permission in 2002 (Stage 1a, four trenches BT3-6). <3>