Now envoys came to him from all sides, from whom he required hostages. To each of their towns he sent sealed letters, and he charged the bearers that they should all deliver the letters on one and the same day, for he had fixed the day by calculating how long it would take to reach the farthest town. The letters commanded the magistrates of all the towns to demolish their walls on the very day they received the order. If there was a day's delay he threatened to sell them into slavery. They, having been lately vanquished in a great battle, and not knowing whether these orders had been sent to them alone or to all, were much perplexed, for if it were to them alone they felt that they were but weak objects of scorn, but if it were to the others also, they feared to be the only ones to delay. Wherefore, as they had no time to send to each other, and the officers who brought the letters urged them to obey, they decided to do so, each town consulting its own safety. And so they threw down their walls with all speed, for when they had once decided to obey they thought that those who did the work most expeditiously would receive most favor. Thus the towns along the river Iberus in one day, and by one act of generalship, levelled their own walls. Being less able to resist the Romans thereafter, they remained longer at peace.