During the execution of these works, Britons came backwards and forwards to the camp freely, and nothing predicted the approach of hostilities; but one day, when the seventh legion, according to custom, had proceeded to no great distance from the camp to cut wheat, the soldiers on guard before the gates suddenly came to announce that a thick cloud of dust arose in the direction taken by the legion. Cæsar, suspecting some attack from the barbarians, assembles the cohorts on guard, orders two others to replace them, and the rest of the troops to arm and follow him without delay, and hurries forward in the direction indicated. What had happened was this. The Britons, foreseeing that the Romans would repair to the only spot which remained to reap (_pars una erat reliqua_), had concealed themselves the previous night in the forests. After waiting till the soldiers of the 7th legion had laid aside their arms and begun to cut the grain, they had fallen upon them unexpectedly, and, while the legionaries in disorder were forming, they had surrounded them with their cavalry and chariots. This strange manner of combating had thrown the soldiers of the 7th legion into disorder. Closely surrounded, and resisting with difficulty under a shower of missiles, they would perhaps have succumbed, when Cæsar appeared at the head of his cohorts; his presence restored confidence to his own men and checked the enemy. Nevertheless, he did not judge it prudent to risk a battle, and, after remaining a certain length of time in position, he withdrew his troops. The 7th legion had experienced considerable loss.[359] Continual rains, during some days, rendered all operations impossible; but eventually the barbarians, believing that the moment had arrived to recover their liberty, assembled from all parts, and marched against the camp. Deprived of cavalry, Cæsar foresaw well that it would go the same with this combat as with the preceding, and that the enemy, when repulsed, would escape easily by flight; nevertheless, as he had at his disposal thirty horses brought into Britain by Commius, he believed that he could use them with advantage;[360] he drew up his legions in battle at the head of the camp, and ordered them to march forward. The enemy did not sustain the shock long, and dispersed; the legionaries pursued them as quickly and as far as their arms permitted; they returned to the camp, after having made a great slaughter, and ravaged everything within a vast circuit. The same day, the barbarians sent deputies to ask for peace. Cæsar doubled the number of hostages he had required before, and ordered them to be brought to him on the continent. In all Britain, two states only obeyed this order.