Bohemond renewed, twenty-two years later, his father’s attacks upon the Byzantine Empire. In the meanwhile, as the result of his share in the first crusade, he had become Prince of Antioch—one of those feudal States which now adjoined the immediate dominions of the Eastern Emperor and exercised considerable social influence on the customs of his subjects. Aided by the Pisans, whose fleet ravaged the Ionian Islands, Bohemond seemed likely to repeat the early successes of his father; but Alexios had learnt how to deal with the Latins, and the Normans’ second assault on Durazzo ended in a treaty of peace, by which Bohemond swore fealty to the Emperor. For the next forty years Greece had nothing to fear from the Normans, but the evil results of the alliance with Venice now became manifest. The Republic of St Mark had jealous commercial rivals in Italy, who envied her the monopoly of the Levantine trade. When, therefore, concessions were made to the Pisans and the previous charter of the Venetians was not renewed, the Empire found itself involved in a naval war with the latter, from which the defenceless Greek islands suffered, and which was only ended by the renewal of the old Venetian privileges. The mercantile powers of Italy had come to treat the Byzantine possessions much as modern European States regard Turkey, as a Government from which trading concessions can be obtained. But every fresh grant offended some one and gave the favoured party more and more influence in the affairs of the Empire. Fresh Venetian factories were founded in Greece, and the increasing prosperity of that country had the disadvantage of attracting the covetous foreigner.