As was so often the case with these Celtic tribes, domestic discord in some degree lightened the labours of the invader. We have seen that Cassivellaunus had obtained by violence the sovereignty of the Trinobantes of Essex. Mandubracius, the son of the dead king, had fled to Gaul and cast himself on the protection of Cæsar, in whose train he returned to Britain. There was still probably a party in favour of the dethroned family, and it was not a mere formality when Cæsar ordered the tribe to accept Mandubracius for their chief, to supply his troops with corn, and to deliver forty hostages into his hands. Five other tribes whose unimportant names are given by Cæsar came in and made their submission; and from them the general learned that not far distant was the town (_oppidum_) of Cassivellaunus, filled with a multitude of men and cattle, and defended by forests and marshes. “Now the Britons,” says Cæsar, perhaps with a sneer, “call any place a town” (_oppidum_) “when they have chosen a position entangled with forests and strengthened it with rampart and ditch, so that they may gather into it for shelter from hostile incursion.” Thither then marched Cæsar with his legions. He found a place splendidly strong by nature and art, but he determined to attack it from two sides at once. After a brief defence, the natives collapsed before the headlong rush of the Romans, and streamed out of the camp on the opposite side. Many were slain, many taken prisoners, and a great number of cattle fell into the hands of the Romans. In order probably to divert the forces of his enemy from his own _oppidum_, the generalissimo Cassivellaunus had sent orders to the four kings of Kent to collect their forces and make a sudden attack on the naval camp of the Romans. The attack was repulsed by a vigorous sortie: many of the Britons were slain and one of their noblest leaders taken prisoner. Hereupon Cassivellaunus, recognising that the fortune of war was turning against him and that his own confederates were falling away, sent messengers to offer his submission and obtain peace through the mediation of his friend, perhaps his fellow-tribesman, Commius. Cæsar, who had his own reasons for desiring a speedy return to Gaul and who doubtless considered that enough had been done for his glory, accepted the proffered submission. He “ordered hostages to be delivered, and fixed the amount of tribute which was to be yearly paid by Britannia to the Roman people. He forbade Cassivellaunus to do any injury to Mandubracius or the Trinobantes,” and with these high-sounding phrases he departed. As he carried back many captives and not a few of his ships had perished in the storm, he had to make two crossings with his fleet, but both were accomplished without disaster. Of Cassivellaunus himself no further information is vouchsafed us, nor do we know what was the fate of the abandoned allies of Rome.