We have now confirmed that the northern half of the trench contains a large cellar, which has been backfilled with a mixture of domestic and industrial waste dating to the end of the 17th century. The backfill is also made up of a range of building materials which are probably from the building that must once have stood above the cellar. This building material has included glazed medieval floor tiles and fragments of decorated wall plaster that together indicate a building of some importance.
Decorated wall plaster (butterfly)
Fragments of window glass and lead cames
The evidence would suggest that the cellar belongs to an earlier incarnation of Cholmondeley's House, and probably the one which was believed to have been destroyed during the English Civil War (1642-46) and so predates the building shown on McGahey's balloon view of 1852.
We are now in the process of excavating the southern half of the trench in order to locate traces of any earlier medieval buildings that may have occupied the area.