A Roman military settlement was first identified during the construction of the Great Western Railway in the 1850s and it became the subject of extensive excavations in the 1970s and 1980s ahead of a road development. It is centred on a round-angled, rectangular enclosure, about 200m north-east to south-west by 140m, with an extensive area of occupation identified to the east, possibly strung out along a road. A medieval castle (Nprn417) occupies the eastern angle of the fort enclosure, with the parish church (NPRN 13509) placed roughly centrally. The excavations identified eight periods of occupation between its establishment around AD 73 - 74 and its abandonment about 120AD. There was a subsequent re-occupation between 260-310AD.

Sources: Ling & Ling 1973 (AC122), 99-144;
1979 (AC128), 13-39;
RCAHMW 1976 (Glamorgan I.2), 86-8 (733)
Marvell & Owen-John 1997 'Leucarum': Britannia Monograph 12.

J.Wiles, RCAHMW, 01 October 2004