FIG. 16. THE WATER-GATE, PORCHESTER
Cardiff.—Although not situated near the Continent, it is probable that Cardiff took its part in the defence of our coast during the Roman period. Whether the Roman fortress at this point formed part of the defences which were placed under the control of the Count of the Saxon Shore may be doubted, but in size and general plan it certainly resembled the coast fortresses of the south-eastern shores.
FIG. 17. PORCHESTER. EXTERIOR OF WEST WALL
In the course of recent excavations in and near Cardiff Castle the nearly complete ground-plan of this castrum was found. Its form was nearly quadrangular, the only irregularity being in the western wall, which was inclined eastward at its southern end. Gates were situated about the middle of the northern and southern walls, whilst semicircular bastions were placed along the walls at intervals, roughly, of about 120 feet. At the angles were built towers of irregular form and of somewhat unusual interest, from the fact that they were obviously additions to the original work. The area enclosed by the walls was roughly a square of 600 feet.
The question of angle towers or bastions is one of considerable importance. Their presence in a Roman castrum may generally be taken as evidence of late date; but it is necessary to bear in mind that in some cases they have certainly been added to give strength to fortresses of early type, which, as we have seen in the cases of Reculver and Brancaster, were furnished with rounded angles, without any such projecting features as angle-towers or bastions. At Cardiff[11] it is perfectly clear that the original building had rounded angles against which towers of irregularly circular plan were subsequently built.
As at Pevensey and Porchester, a Norman castle was ingeniously constructed within this castrum by placing the mound towards the north-western corner. Two walls thrown out from this, one towards the western wall and the other to about the middle of the southern wall, enclosed practically a quarter of the whole area in the south-western angle, and formed the inner court, whilst the whole of the rest of the area of the castrum formed the outer court. It is obvious that at the period when this Norman castle was built the Roman walls were sufficiently perfect to afford an effective barrier of defence.