D. 4.--The Iceni had long ago taken care to fortify this approach to their land. The whole space between fen and forest in the Cam valley was cut across by four (or five) great dykes which may still be traced, constructed for defence against invaders from the westward. Of these, the two innermost are far more formidable than the rest, the "Fleam Dyke" near Cambridge, and the "Devil's Ditch" by Newmarket. The outer fosse of each is from twenty to thirty feet deep; and the rampart, when topped by a stockade, must have constituted an obstacle to troops unprovided with artillery which the Iceni might justifiably think insuperable. The "one narrow entrance" along the whole length of the dykes (five miles and ten miles respectively) is where the Icknield Way cuts through them. D. 5.--Here then, probably, the Icenian levies confidently awaited the onslaught of Ostorius--the more confidently inasmuch as he had not waited to call up his legionaries from their winter quarters, but attacked only with the irregulars whom he had been employing against the marauders in the midlands. The Iceni, doubtless, imagined that such troops would be unequal to assaulting their dyke at all. But Ostorius was no ordinary leader. Such was the enthusiasm which he inspired in his troops that they surprised the revolters by attacking along the whole line of the Fleam Dyke at once, and that with such impetuosity that in a moment they were over it. The hapless Iceni were now caught in a death-trap. Behind them the Devil's Ditch barred all retreat save through its one narrow entrance, and those who failed to force their way through the mad crush there could only fight and die with the courage of despair. "Many a deed of desperate valour did they," says Tacitus [_multa et clara facinora_], and the Romans displayed like courage; the son of Ostorius winning in the fray the "civic crown"[163] awarded for the rescue of a Roman citizen. But no quarter seems to have been given, and the flower of the Icenian tribe perished there to a man. D. 6.--This slaughter effectually scotched the rising which the Icenians were hoping to organize. All Central Britain submitted, and, we may presume, was quietly disarmed; though the work cannot have been very effectually done, as these same tribes were able to rise under Boadicea twelve years later. The indefatigable Ostorius next led his men against the Cangi in North Wales[164] (who seem to have been stirred to revolt by the Icenian Prince Antedrigus), and gained much booty, for the Britons dared not venture upon a battle, and had no luck in their various attempts at surprise. But before he quite reached the Irish Sea he was recalled by a disturbance amongst the Brigantes, which by a judicious mixture of firmness and clemency he speedily suppressed. And all this he did without employing a single legionary.