Loughor Castle lies within the eastern angle of a Roman military enclosure. The earliest medieval remains appear to be a primary ring bank constructed between 1106 and 1151. In the second half of the twelfth century the bank was extended inwards and two stone buildings were raised in the late twelfth to early thirteenth century. The main curtain wall was added in the later part of the thirteenth century. In the late thirteenth century the square tower that is the prominent survival on the site today was inserted into the curtain wall.
Source: RCAHMW 1991 (Glamorgan III.1a the Early Castles), MR4 265-74.
RCAHMW, February 2011