Week 13-15 (6-24 September)

Although the site was now closed to the public, a small team remained to tie up a few loose ends prior to backfilling the site. That was the plan anyway.

A Roman bone fitting with one copper alloy river still in place (25mm long)

In Trench 3, the ash and charcoal deposits were found to be filling a large, irregular 1m deep pit. The function and date of this feature is at present uncertain. It could be a prehistoric feature; it may be associated with activity taking place against the inside of the first Roman (turf) rampart of the fortress; or it could still be a quarry pit, used to extract material to form a marker bank at the rear of the second rampart. The second option is favoured at present, and it could mean that the cobble surfaces and stone features found above the charcoal layers also represent activity contemporary with the first rampart. The pit was cut into natural sandy subsoil over glacial clay. We had reached the bottom of Trench 3, some 3.3m below the current ground level!

The lowest deposit in the pit under excavation

In Trench 4, what was meant to be a cursory investigation of the medieval cobble wall foundation revealed a substantial mortared stone wall beneath! This was a pleasant surprise, as taken with the evidence from Trenches 1 and 2 it offers a plausible construction sequence for the infirmary. Apparently the mortared wall in Trench 4 joined with the Roman interval tower SW6 to the south-west and formed the south-east end of the original infirmary (around 1100). The massive cobble foundation found in Trenches 1 and 4 is evidently a replacement south-east infirmary wall, indicating that Tower SW6 was demolished some time between about 1100 and 1250. Then the infirmary was extended to the south-west, on massive concrete and rubble foundations, around 1250.

A detailed view of the original infirmary wall (under the scale), buried by the later cobble foundation (centre)
Part of a honestone (90mm long)

In Trench 5, excavation of the deposits overlying the foundations of the Multangular Tower and cut by the possible timber staircase feature produced a wide range of Roman finds. The most intriguing was a bone counter, inscribed with decoration and Latin text on both sides, which is almost identical with a group of counters found in London; plenty of scope for research there!

Melon bead (diameter 20mm)	Decorated bone counter with the legend IVNIII (diameter 16mm)

A revelation - the deposits containing wall plaster appear to fill a large pit situated over the foundations of the Multangular Tower. The explanation favoured at present is that the rear of the tower was dismantled, possibly soon after it was built, due to structural instability (see Week 12, Trench 6). A rampart was then built against the surviving front half of the tower, forming a continuous rampart around the west corner of the defences. Access to the rampart via the Multangular Tower was no longer possible, hence the construction of a timber staircase onto the rampart as indicated in Trenches 3 (in 2003) and 5. When these changes took place, and how the front of the Multangular Tower was used thereafter, requires careful study of the excavation data.

View of the Multangular Tower looking west, showing the continuation of the south wall foundation in Trench 5

This scenario also has implications for the medieval infirmary. It would mean that there was no Roman tower to form the north-west end of the infirmary. The column base foundation found in Trench 5 would represent the continuation of the vaulted undercroft over the former position of the tower and presumably right up to the north-west fortress wall. In this case, the length of the infirmary would have been about 47m, rather than the 29m indicated by the 19th century excavators; a truly massive building.

Beneath the rampart and cut by the foundations of the Multangular Tower was a series of deposits including a cobble surface; these deposits are presumably contemporary with the first fortress rampart. They overlaid a possible buried soil overlying natural sand. A small pit or post-hole, cutting the buried soil, could be prehistoric in date. Anyway, we had reached the bottom of Trench 5.

In Trench 6, the dump layers in the western part of the trench were excavated down to natural sand. They were very organic, and contained wood fragments and blocks of turf. Are these the remains of the turf rampart, spread out to form the terrace on which the Multangular Tower was built? Close examination of the tower foundations in the eastern part of the trench indicated that they had been dug into natural sand. This suggests the original ground surface in the west corner of the fortress was quite flat, but then dropped off steeply down to the River Ouse. Hence the need to provide a terrace on which to build the projecting front of the Multangular Tower, and so the need to support the projecting front on timber piles in such unstable ground. It also might explain the omission of timber piles beneath the rear of the tower by the Roman builders as belief that the flat, sandy subsoil could support the weight of the tower - mistaken as it turns out.

And so the excavation finished, followed by a week of dismantling the site and backfilling the trenches. Thanks to everyone who helped to make the project such a success: the project team of course; the YAT staff who helped with the off-site activities; the 65,000 people who paid to see the dig; and not least, the 800 or so trainees who carried out most of the actual digging and paid for the privilege. Now starts the assessment of the stratigraphy, finds and environmental evidence. No doubt this will fill in many of the blanks in the story we have pieced together, as well as overturning many of the hypotheses that have been formulated over the past 4 years! Watch out for updates on the assessment, and news of how the results will be published.

The final team photo