From the summits of their cliffs the Britons had perceived this formidable expedition, and had sought refuge in the vast forests which cover their shores. Cæsar marched forward to drive them back into their retreats, when a violent tempest destroyed forty of his ships and drove a great number ashore. The first care of the conqueror was to protect his fleet against the fury of the sea and the hostility of the islanders. He caused all his vessels to be hauled ashore, in order to surround them afterwards by a strong intrenchment. His largest galleys were diminutive in comparison with our vessels of war. His transport ships were hardly more than barges. The Roman soldiers labored without intermission ten days and ten nights before they had rendered their fleet secure. They then resumed their march against the Britons, whose army was still increasing. All the chiefs had united their forces under the orders of a commander-in-chief, Cassivelanus, king of the Cassii, renowned for his bravery and skill. The Britons avoided a general engagement. Assailing the Romans incessantly with their cavalry and their war-chariots, which they conducted with the ease of habit even along the edge of precipices, they retired again into the forests from the moment that the advantage was no longer on their side. But this barbarian intrepidity was not accompanied by experience. Cæsar's cavalry, supported by three legions, having scoured the country in quest of forage, the enemy had remained concealed all day, when suddenly they issued in a mass from the neighboring forests and swept down upon the Romans who were scattered about the country. {13} Already the Britons imagined themselves victors; but the well-disciplined Roman detachments formed again as if by enchantment, the horsemen rallied, and the Britons, enclosed in a formidable circle, sustained losses so great that on the morrow the allies of Cassivelanus nearly all deserted him and returned into their territories, leaving him to face the Romans unsupported. The king in his turn fell back upon his kingdom, which was situated on the left bank of the Thames.