Professor Haverfield has gathered together other signs of rebuilding further south in inscriptions at Brough in Derbyshire, at Newcastle, and at Netherby.[1] In all of these he has pointed out that there occurs, as at Birrens, the name of the Governor Julius Verus, and that all of these sites, including Birrens, lay within the limits of the territory of the Brigantes, a tribe to which more than one allusion, significant of their fighting strength and love of freedom, has survived in the pages of Roman writers. It seems probable then that the necessity of quelling a Brigantian uprising about A.D. 158 involved a loosening of the hold on the Vallum, and that such forts as Birrens and Newstead were then lost at least for a time.

The reoccupation of the fort opens the final chapter of its history. Once more there was considerable alteration and rebuilding. The reducing wall was thrown down, buildings were restored and a larger garrison installed. But if we may judge from such worn foundations as have survived, the reconstructed buildings had less of the element of permanency than those that preceded them. Here and there, built into the later walls, or in the masonry of the main outlet of the drains on the west, or again employed as drain covers, there were found blocks which had obviously formed part of earlier buildings. They were distinguishable from those beside them by their greater size, and by the fineness of their dressing. Clearly, in the final occupation, the hold on the north was slackening. And then, probably somewhere early in the reign of Commodus, when we know that the British war was pressing heavily, must have come the end. The Roman grasp of the Vallum must have given way, and with it their hold of the supporting forts, such as Birrens and Newstead. How these fell it is improbable that we shall ever know, and yet traces of the catastrophe which overwhelmed them have been revealed to us, after the lapse of many passing centuries. It is the secret drawn from the wells and rubbish pits—a tale of buildings thrown down; of altars concealed, thrown into ditches or into pits, above the bodies of unburied men; of confusion, defeat, abandonment; of a day in which the long column of the garrison wound slowly southward across the spurs of the Eildons, leaving their hearths deserted and their fires extinct.

1 Proceedings of the Society of Antiquaries of Scotland, Vol. xxxviii. p. 454.