These preparations were all indispensably requisite; for in the battle which ensued, the Vanni and their allies fought their ships with a skill and a valour of which the Romans had not had any previous example; and they would certainly have been beaten, if they had not, by means of sharp engines, cut the ropes and sails of the hostile fleet, and thus rendered their ships unmanageable: in this state they were easily and speedily captured. As the Vanni had on this occasion mustered all their forces, their defeat put an end to their resistance, and removed Caesar's principal obstacle to the invasion of Britain. The motives which induced Caesar to invade Britain can only be conjectured, if, indeed, any other motive operated on his mind besides ambition, and the love of conquest and glory; stimulated by the hope of subduing a country, which seemed the limit of the world to the west, and which was in a great measure unknown. He was, probably, also incited by his desire to punish the Britons for having assisted the Vanni; and Suetonius adds, that he was desirous of enriching himself with British pearls, which were at that time in high repute. Before he undertook this expedition, which, even to Caesar, appeared formidable, he resolved to learn all he could respecting Britain. For this purpose, he collected the merchants who traded thither from all parts of Gaul; but they could afford him no satisfactory information. They had visited only the opposite coast of Britain; of the other parts of the country, of its extent, its inhabitants, &c., they were utterly ignorant. Under these circumstances, therefore, he sent one of his officers in a galley, who, after being absent five days, during which however he had not ventured to land, returned to Caesar, and acquainted him with the little he had observed. Caesar resolved to invade Britain immediately: for this purpose, he ordered eighty transports to take on board two legions; and the cavalry to be embarked in eighteen more, at a port a few miles off. The enterprize was attended with considerable difficulty, from the opposition of the Britons, and the large ships of the Romans not being able to approach very near the land. It was however successful, and the Britons sued for and obtained peace.