Internet Archaeol. 14. Haslam. Part 2 - reassessment of earlier excavations, period 2.

PART 2 - EARLIER EXCAVATIONS: A REASSESSMENT

Periods 0-1 | Period 2 | Period 3 | Periods 4-5

Period 2A: The wall | Rear wall
Period 2B: Introduction | Deposits on the berm | Stones inside the bank

The wall

There is little information that can be added to that derived from earlier excavations concerning the structure or dimensions of the wall added to the front of the original bank in period 2. A plinth formed by the lowest course on the outer face of the wall, already noted in a number of places, was also present on the west side of the south-west corner.

What is open to reassessment, however, is the evidence for both its physical and temporal relationship to the bank. In discussing the structure of the front revetment (above) it has already been shown that, except in one or two cases (possibly trench W.XX (E10) on the north-east corner), the front of the bank was neither cut back with a sloping outer face for the insertion of the wall, nor was the space behind it subsequently filled with mixed materials (as Radford concluded, 1972, 105, and 70-1). It is clear that in nearly every case where it was investigated, the truncated front turf revetment remained as a vertical or near-vertical face against which the inner face of the wall was built. This so-called "filling" cannot therefore be adduced as independent evidence for the insertion of the wall, as Radford claimed. In other respects, however, I agree with Radford that the wall was inserted into the front of the bank, and disagree with Wainwright, who thought that the wall was contemporary with it. This is brought out in Wainwright's comments on his several trenches across the front of the bank in the north-east corner, and Radford's response to Wainwright's interpretations (1972, 72-3). (However, in one place, in his discussion of Knocker's trenches (1972, 87), Radford appears to accept the view 'that bank and wall are contemporary'.)

It is quite clear, however, from the evidence of section 4 in the south-west corner, that the front turf revetment was indeed cut back to receive the wall. It has been argued that at this point the base of the wall rested on a shelf of this same turf revetment. (This observation is at variance with Radford's observation on the same section (R.V, 1972, 80) that the wall was 'set on a level base cut at the back to a depth of 8 inches into the old turf line'.) From this evidence, and from observations in other trenches around the defences, it appears that the front revetment of the bank was cut back only so far as was necessary to accommodate the thickness of the wall. It is assumed (though this cannot be unequivocally demonstrated) that this was done in such a way that the front of the wall was aligned with the original front of the turf revetment. The lowest course of the front edge of the wall was also observed in many trenches to have been placed in a depression or a narrow trench cut to receive this front course when the wall was inserted.

In many places the wall appears to have been laid onto a layer of dark humus or soil (as above paragraph), or into a slight trench which contained this soil (as in W.XI and W.IX [E-W trench]). In other cases the lowest front stones of the wall were placed in the 'slot' (mentioned above) which itself contained some of this soil - a feature noted in several places in the 1975 excavations). This raises doubts as to whether this slot was the remains of a palisade trench of period 1. However, this fill of soil within this feature - and in some cases on the berm, as well as in the shallow trench sometimes cut to receive the wall - is more likely to have been the result of digging out the front of the bank, which consisted mainly of this soil in the form of old turves, for the insertion of the wall. This operation would have inevitably led to the spreading of much humus-rich material around the working area while it was being shifted (it is presumed) to the top of the bank. This is shown clearly in, for instance, W.IX [E-W trench].

A feature noted on the south-west corner as being apparently associated with the construction of the wall, was a localised layer or wedge of clay, often containing a few stones, packed around the base of the rear face of the wall. This has been noted in many other places around the defences, particularly in trenches W.II, W.VI, XIII (N-S section), and W.XX (E10, and other sections). Radford's interpretation of this feature as a drain (1972, 105) must be doubted, in view of the fact that the back of the wall would never have been open to the weather. It must merely have served to stabilise the lower courses of the back of the wall, and would perhaps also have prevented (whether intentionally or not) the bonding mortar from being leached by rainwater which had soaked through the comparatively acid turf revetment.

The significance of the observations about the relationship of the wall to the bank lies in their implication that the wall was inserted into the front of a bank built with a fronting turf revetment which was still substantially intact, and that it was therefore built after a rather shorter interval from the initial construction of the bank than has hitherto been thought. Furthermore, it can also be inferred from the presence of weathering products on the berm that a considerable period elapsed between the construction of the wall and its destruction in the early 11th century (period 3). These conclusions are discussed further in Part 3.

Rear wall

It has been suggested above that the construction of a relatively slight wall built on the back of the bank as a rear revetment to a wall walk also belongs to this phase. This would possibly have been made necessary by the addition of the extra material removed from the front revetment to the top of the bank.

It has been noted above in the discussion of the intra-mural walkway (period 1) that a spread of stones strewn across a wide area behind the bank has been recorded in nearly every one of the sections dug inside the bank. As has been mentioned, this has invariably been misinterpreted by Radford as a street running behind the bank, and has been marked as such on all his plans. However, it is clear from evidence on all sides of the defences that this spread of stones formed a layer which was quite distinct from, and in all cases overlaid, the flat laid stones of the walkway itself, and was spread for some distance beyond (inside) it. The stones in this layer were generally of considerable size, and are unlikely therefore to represent either the metalling of a street, or the remains of an episode of robbing of a former stone feature.

The only plausible explanation for this scatter, noted around the entire length of the defences, is that it represents deposits which resulted from the destruction of a stone-built feature which was originally placed either at the top or part-way down the back of the bank. The logical inference is that this was contemporary with the wall added to the front of the bank. Some of these stones, in particular those lying on the intra-mural walkway at the rear edge of the bank, may well have come from the partial collapse of this wall during the period of neglect of the defences in period 2B. However, the fact that many large stones were spread as a wide scatter beyond the back of the bank suggests that the stones from this wall had been forcibly thrown backwards from near the top of the back of the bank. The fact that no deposits containing mortar were noted at the back of the bank implies, firstly, that these stones were not derived from the destruction of the front stone wall and, secondly, that this feature was a separate structure of dry-stone build placed at some point on the rear face of the old bank. Although this rear revetment wall nowhere survives in situ, it can be seen as a logical, and indeed necessary, element in the programme of refurbishing the defences which is represented by the addition of a new stone wall to the front of the bank.

Period 2B

There are several different stratigraphical observations which combine to indicate that the defences were abandoned as a functioning system over a relatively long period of time. These are:

the partial collapse of the rear revetment wall down the back of the bank;
the loss of the use of the intra-mural walkway;
the slow accumulation of weathering products on the berm and at the back of the bank;
the erosion of the sides of some of the ditches with the deposition of the same weathering products in the erosion hollows.

This process is argued below as having occurred in the more stable conditions prevailing in the six or seven decades of the 10th century after c. 930. All these deposits have been recorded in earlier excavations.

Deposits on the berm

The excavations on the south-west corner, in particular in trench 2), showed a layer of mixed materials underlying the destruction deposits of the wall (period 3). This is interpreted above as having accumulated over a long period while the wall was in position. It could, however, also include construction debris from the building of the wall, as well as material thrown up from the cleaning of the ditches in period 2C. A similar division of layers on the berm has also been noted on other parts of the defences. Radford himself draws attention to this, and states (1972, 105) that 'It is possible - and the field note-book [of Wainwright] provides some confirmation - that the [phrase] "spill from wall", etc., was used to describe a double layer, the two components of which were not readily separable...' They were however separated on Wainwright's section of trench W.IX (south-east corner, E-W section), and also in Knocker's trench K.I (west side, 1972, 86). In the former case this lower deposit could be interpreted as the filling of an erosion hollow in the inner edge of the inner ditch (see above).

Stones inside the bank

Stones from the wall added to the back of the bank may well have started to collapse down the back of the bank during the period of neglect of the defences in period 2B. This deposit is discussed above.

Periods 0-1 | Period 2 | Period 3 | Periods 4-5