426 THE DECLINE AND FALL CHAP. A stupendous mole, raised across the entrance of the ^^^^' harbour, intercepted all hopes of relief. The town A. D. 292. surrendered after an obstinate defence; and a consi- derable part of the naval strength of Carausius fell into the hands of the besiegers. During the three years which Constantius employed in preparing a fleet ade- quate to the conquest of Britain, he secured the coast of Gaul, invaded the country of the Franks, and de- prived the usurper of the assistance of those powerful allies. A.D. 294. Before the preparations were finished, Constantius His death, j-eceived the intelhgence of the tyrant's death, and it was Considered as a sure presage of the approaching victory. The servants of Carausius imitated the ex- ample of treason which he had given. He was mur- dered by his first minister AUectus, and the assassin succeeded to his power and to his danger. But he possessed not equal abilities either to exercise the one, or to repel the other. He beheld, with anxious terror, the opposite shores of the continent, already filled with arms, with troops, and with vessels; for Constantius had very prudently divided his forces, that he might likewise divide the attention and resistance of A.D. 296. the enemy. The attack was at length made by the Bi^tain by° Principal squadrou, which, under the command of the Constat!- prefect Asclepiodatus, an officer of distinguished merit, had been assembled in the mouth of the Seine. So imperfect in those times was the art of navigation, that orators have celebrated the daring courage of the Romans, who ventured to set sail with a side wind, and on a stormy day. The weather proved favourable to their enterprise. Under the cover of a thick fog, they escaped the fleet of Allectus, which had been stationed off the isle of Wight to receive them, landed in safety on some part of the western coast ; and convinced the Britons, that a superiority of naval strength will not always protect their country from a foreign invasion. Asclepiodatus had no sooner disembarked the imperial troops, than he set fire to his ships ; and as the expe-
