RCAHMS Special Survey 2015, Mottes

Two Lanarkshire castles and two in Sutherland were surveyed in 2015. Of the former, Abington motte-and-bailey castle was planned in the early spring, and Coulter (Wolfclyde) motte in June, at the launch of the Discovering the Clyde Programme. The mottes at Proncy and Invershin in Sutherland were both recorded in May, again as part of the RCAHMS contribution to the Early Stone Castles project, this time focusing on earthwork and timber castles.

The two Lanarkshire castles initially appeared to be very different structures, there being no recorded outworks at Coulter. However, close examination of the ground revealed evidence for a possible bailey on the S side of the motte alongside the River Clyde. The line of the bailey ditch on the S is marked by a distinct terrace in the road past the motte and as a slighter terrace across the paddock to the E. There is no visible evidence of the ditch in the next paddock to the E, but the return is traceable to the N running up to the motte. This is a major change in our understanding of the site.

By contrast, neither of the two mottes at Proncy and Invershin display any trace of a bailey, but are much larger in size, measuring 25m and 40m respectively across the top as opposed to about 12m at the Lanarkshire sites. Both were defended by ditches, of which that at Proncy is now partly occupied by a mill pond, suggesting it was originally fed by a spring and held water, while that at Invershin may have been a dry moat. Both mottes display traces of buildings on the top, suggesting that they continued in use into the late medieval period. At Proncy there are the stone and mortar ruins of perhaps two buildings on the summit, the edge of which is marked by a stone revetment wall with a possible entrance on the SW. Three buildings are evident as low stony banks in the undergrowth at Invershin.

RCAHMS (DES 2015, 190)