Concerning the defensive works erected in the British Isles during the Saxon Period there is more indefiniteness prevailing at the time of writing than there is with regard to any period antecedent or consequent to it. This may be attributed to two causes, the first being the unsatisfactory use of the word _burh_ in Anglo-Saxon manuscripts, and the second the effects produced during the past half-century by writers wrongly attributing the remains of early Norman castellation to the period preceding it, following upon a misunderstanding of the word above mentioned. This has had the result of rendering the major portion of the works produced upon the subject of castellation during the latter half of the nineteenth century unreliable and obsolete so far as the Saxon and Roman periods are concerned, while at the same time producing a marked hesitancy among experts to definitely attribute any work to the first of the periods without systematic excavation of the site. In O.E. the word _burh_ in its nominative form signifies a fort or stronghold and is generally translated as "borough," while in its dative form _byrig_ it is commonly used to indicate what its modern representative "bury" conveys. But Anglo-Saxon writers did not use the two words strictly, and thus hesitancy and confusion have been produced. It is now being generally accepted that the usual form of burh or borough was that of a rectangular enclosure surrounded by a rampart and an external ditch, the area being of any dimensions up to 20 or 30 acres or more. This arrangement is probably exemplified in the earthworks at Wallingford. It is obvious that the inherent weakness in this very elementary system of defence lies in the inability to adequately man all the ramparts at once because of their great extent; the defenders probably relied upon the promptness with which they could meet a threatened attack at any particular point. The Anglo-Saxons at a very early period recognised the advisability of forming fortified positions in the island, and carried out the system so entirely that practically every isolated house, farm, or group of buildings was enclosed by its rampart and ditch. Even at the present day we become aware of this fact from the scores of "burys" and "boroughs" with which the surface of our land abounds. The burh was thus a comparatively slight affair when compared with earthworks which had preceded it.