surrendered and again consented to become an Athenian dependency, and to pay both the same tribute for the future as in the past, and to make good to Athens all arrears which had accumulated since the revolt.
Previous to the surrender, Alcibiades began preparations for the more serious and important task of the capture of Byzantium. For this his present resources were not adequate, and he thought it prudent to strengthen himself with an increase of funds and of military force. His first step was to attack Selymbria, on the northern shores of the Propontis, and about fifty miles to the west of Byzantium. It, too, had been a colony from Megara, and it had no doubt passed, along with Byzantium, into the power of Athens. It would have been sure to take part in the revolt of that city from Athens. Alcibiades contrived to secure possession of it by means, it is said, of the treacherous connivance of some of its citizens. Now he was able to get a supply of money, and thus to levy an army from the neighbouring Thracians, always a warlike people, and very formidable when properly led. As soon as the terms of submission had been fixed for Chalcedon, he resolved to attempt the recovery of Byzantium. He advanced on it by land from Selymbria, and began the siege of the city, the first of much importance, in a long series of memorable attacks. The place could be reduced only by regular military operations, and in these, when applied to fortified positions, the Greeks were never very skilful. The siege of a city was certain to be tedious. It was as difficult and hazardous to attempt to carry a strong fortress by assault as it is in
