The Castle occupies an irregular oblong area divided into a larger and smaller ward by a transverse wall, which is carried across at one of the narrowest parts; thus where breadth is unobtainable, as at Conway and Carnarvon, ward is set behind ward. Eight lofty circular towers are arranged at intervals around the massive curtain wall, four of them being provided with small look-out turrets upon their summits. In the larger bailey the banqueting hall and domestic apartments were placed.
The Castle and also the town fortifications were erected by King Edward I., with Henry de Elfreton as the architect; they were completed in 1284, and occupied by the King and Court in 1290, upon the occasion of a Welsh rising. The monarch, however, was nearly starved out in his fortress through an unusual flood whereby provisions were unable to be sent across the river. Previously, however, he had passed a Christmas there and the assertion that Conway was really a combination of a castle, a palace, and a pleasant residence is perfectly legitimate. Richard II. assembled his forces at Conway to resist the invasion of Bolingbroke, but was induced to leave it, and his betrayal and lodgment in Flint Castle followed. The edifice suffered but little during the Wars of the Roses; Henry VII. repaired it where decay had taken place, and it practically remained intact until the Great Rebellion, when it suffered from two sieges, and shortly afterwards, in 1665, was despoiled of its timber, lead, and iron, and reduced to its present condition. The excellence of the masonry which characterises the Edwardian castles in Wales is perhaps in no way better exemplified than at Conway, where a portion of the base of a tower on the south side fell out bodily in recent times through being undermined, and gave much trouble before it could be broken up. It has since been restored. The protection of the Castle is now in the hands of the town authorities of Conway.
Beaumaris Castle was erected by King Edward I. about 1295, and approximates more to the concentric ideal than perhaps any other castle in Britain. The outer enceinte is an almost regular octagon, strengthened by towers at each of the angles and in the centre of each curtain, excepting the one in which the entrance gateway is placed. The inner enceinte is square in shape and of very great height, thus commanding the ramparts of the outer; it has the usual towers, of immense strength, and is finished with a grand array of battlements. Its position probably detracts from impressiveness, for it was designed to have the moat surrounding it filled with water at every tide from the Menai Strait, and this necessitated the selection of low ground for a site. By the arrangement of the walls two baileys are formed, the inner and outer, and the Castle affords an example of a fortress built upon the concentric ideal where the ground does not modify the detail in any way.
Carnarvon Castle may be confidently claimed as the finest example of its type in Europe. It stands upon a site previously unoccupied and was commenced by King Edward I., who raised the walls sufficiently high to cover the garrison, and completed by his son, Edward II., who carried the walls and towers to their present altitude. It is built of limestone blocks with string-course bands of dark-brown sandstone, the mouldings, doorways, and other ornamental portions also being of the same material. The plan of the Castle approaches that of a kidney form, the whole of the space enclosed forming one ward in contradistinction to that at Conway, which is subdivided; as the ancient town of Carnarvon was surrounded by massive walls, large portions of which still remain, the area so enclosed may be looked upon as the outer bailey.
Although the enceinte of the Castle is plentifully supplied with towers which undoubtedly form the chief feature of its picturesque appearance, yet it is to be questioned if the latter added very materially to its powers of resistance when compared with the walls, which are in places over 15 feet in thickness, and of very great height, often over 100 feet. These walls contain, at the points most vulnerable to an attack, a double line of galleries traversing the thickness and leading easily into each other for mutual support. The outer walls of these passages are plentifully supplied with loopholes, and as the merlons upon the battlements are also pierced with oillets, a triple discharge of quarrels and arrows could be brought to bear upon assailants by a garrison securely protected from injury. Against such a hail of missiles any attack would probably prove futile.
The moat is of great width and depth and formed no inconsiderable portion of the original defences. The main idea of the architect when planning Carnarvon Castle appears to have been to render attacks upon the general line of the enceinte impossible of success, by reason of the galleries and the thickly-set mural towers, and thus to lead the assailants to concentrate upon the chief entrance. This, however, was protected primarily by the town walls, then by a formidable moat, two massive towers, a narrow entrance furnished with no less than four portcullises, with two inner obstructions of a similar nature to be overcome ere the entrance was forced. Such an elaborate concentration of effective resistance is seldom encountered in medieval fortresses, and the fact that Carnarvon Castle has never been taken by assault, but only subdued by starvation, is amply accounted for.
This magnificent structure has always been a Crown possession, and at the present time is preserved with a care deserving of all praise. It narrowly escaped demolition at that period which proved so fatal to all castles in Britain, but, although the order was issued, the carrying out was delayed, and the accession of Charles II. in 1660 nullified it. The chief architectural beauty is perhaps the Eagle Tower, crowned with its three graceful turrets and boasting of the birth within its walls of the first Prince of Wales, but the traditional apartment is still problematical.