Explorations in Rome, 1871, 1872

The identification of an eighteenth-century plan and a set of nineteenth-century photographs, in conjunction with a new survey of its remains, has permitted the reinterpretation of an early eleventh-century building at Avranches, in the Département of Manche, Normandy. This has shown that it measured 37 m by at least 27 m, was at least 16 m high, and that it can be considered as a donjon or ‘keep’, or, as now more usually termed, a ‘tour maîtresse’ or ‘great tower’. The remains of the building and its interpretation are described, with the aid of plans and the key material referred to above. Among the largest ‘great towers’ known (at least in plan) and one of the three known pre-Conquest examples in the Duchy, it is of great significance to the rapidly advancing study of this class of building.