XVIII. In his campaigns he was chiefly remarkable for caution, for he would not, if he could help it, begin a battle of which the issue was doubtful; nor did he wish to emulate those generals who have won themselves a great reputation by running risks, and trusting to good luck. But he ever used to say to his countrymen, that none of them should come by their deaths through any act of his. Observing that Tolmides, the son of Tolmaeus, elated by previous successes and by the credit which he had gained as a general, was about to invade Boeotia in a reckless manner, and had persuaded a thousand young men to follow him without any support whatever, he endeavoured to stop him, and made that memorable saying in the public assembly, that if Tolmides would not take the advice of Perikles, he would at any rate do well to consult that best of advisers, Time. This speech had but little success at the time; but when, a few days afterwards, the news came that Tolmides had fallen in action at Koronea, and many noble citizens with him, Perikles was greatly respected and admired as a wise and patriotic man.
XIX. His most successful campaign was that in the Chersonesus, which proved the salvation of the Greeks residing there: for he not only settled a thousand colonists there, and thus increased the available force of the cities, but built a continuous line of fortifications reaching across the isthmus from one sea to the other, by which he shut off the Thracians, who had previously ravaged the peninsula, and put an end to a constant and harassing border warfare to which the settlers were exposed, as they had for neighbours tribes of wild plundering barbarians.