The protection obtained by the Trinobantes engaged the Cenimagni, the Segontiaci, the Ancalites, the Bibroci, and the Cassi (_see p. 168_), to follow their example. The deputies of these different peoples informed Cæsar that the _oppidum_ of Cassivellaunus (_St. Albans_) stood at a short distance, defended by marshes and woods, and containing a great number of men and cattle.[407] Although this formidable position had been further fortified by the hands of men, Cæsar led his legions thither, and attacked it on two points without hesitation. After a feeble resistance, the barbarians, in their attempt to escape, were slain or captured in great numbers. Nevertheless, Cæsar was operating too far from his point of departure not to tempt Cassivellaunus to deprive him of the possibility of returning to the continent, by seizing upon his fleet. In effect, Cassivellaunus had ordered the four kings of the different parts of Cantium (_Kent_), Cingetorix, Carvilius, Taximagulus, and Segovax, to collect all their troops, and attack unexpectedly the camp in which the Roman ships were inclosed. They hastened thither; but the cohorts did not leave them time to attack; they made a sortie, killed a great number of barbarians, captured one of their principal chiefs, Lugotorix, and re-entered their camp without loss. On the news of this defeat, Cassivellaunus, discouraged by so many reverses and the defection of several peoples, employed Commius to offer his submission.[408] [Sidenote: Re-embarkment of the Army.] VIII. Summer approached its end (they were in the last days of August). Cæsar, aware that there no longer remained sufficient time to be employed with advantage, prepared for his departure; he wished, moreover, to pass the winter on the continent, fearing sudden revolts on the part of the Gauls. He therefore caused hostages to be delivered to him, fixed the tribute to be paid annually by Britain to the Roman people, and expressly prohibited Cassivellaunus from all acts of hostility against Mandubratius and the Trinobantes.