The excavation described below was undertaken by the writer on behalf of the Ministry of Works and the Royal Commission on Historical Monuments, but the present article is his own sole responsibility.
The defences of the Legionary Fortress at York were first scientifically examined by the late S. N. Miller in 1925–8 and the report on the work in 1925–7 appeared in this Journal. As a result of his work we have a satisfactory framework into which to fit subsequent and previous discoveries. The structural sequence arrived at by Miller can be briefly summarized as follows:—
Period 1. A campaigning base deduced by Miller from occupation earth in what he considered to be part of the clay rampart of Period 2 and dated by him to the beginning of the governorship of Petillius Cerialis (A.D. 71–4).
Period 2. The first defences of which Miller recognized structural evidence consisted of a massive rampart of clay, dated by him to the close of the governorship of Cerialis.
Period 3. In the early part of the second century stone gates and towers were built and linked by a stone wall. The south-east gate was built in A.D. 108–9, but some work was still being done in Hadrian's reign. The clay bank of Period 2 remained behind the stone wall.
Period 4. At the end of the second century there was an extensive restoration under Severus. A new stone wall was built, at any rate on the south-east side, immediately behind the wall of Period 2 which was completely removed except for the foundations.
Period 5. At the turn of the third and fourth centuries the south-west and north-west sides and part of the north-east side were reconstructed, with projecting multangular corner and interval towers on the river front (fig. 9).